Antimicrobial susceptibility patterns of Streptococcus pneumoniae over 6 years at Gondar University Hospital, Northwest Ethiopia

Objective:To assess the magnitude and antimicrobial susceptibility patterns ofStreptococcus pneumoniaeisolates from various clinical specimens.Methods:A record based on retrospectivestudy was conducted at Gondar University Teaching Hospital from September 2007 to January 2012.All patients who visited Gondar University Hospital and provided clinical specimens(body fluids,discharge,swab and blood)for routine bacteriological culturing and antimicrobial susceptibilitytesting were taken for analysis.Clinical specimens were processed for bacterial culture accordingto the standard procedures.Antimicrobial susceptibility test for isolated organisms was doneusing agar disk diffusion method.The data were entered and analyzed using SPSS software version16 package.Results:One hundred and fifty threeStreptococcus pneumoniaewere isolated frompatients who visited Gondar University Teaching Hospital bacteriology laboratory for culture.Majority of the pneumococcal isolates were from inpatients[111(72.5%)],and 74(48.4%)were frombody fluids.Out of the total isolates,93(61%)were found to be resistant to at least one antibioticused for susceptibility testing.Forty eight(43.2%)of the isolates were multi-drug resistant(resistantto two or more drugs).The resistance rate noted for both ciprofloxacin 17(11.1%)and ceftriaxone15(9.8%)were alarming.Conclusions:High proportions of the isolates tend to be increasinglyresistant to the commonly prescribed drugs.The recommended drug of choice like ciprofloxacinand ceftriaxone were found to be less susceptible in the study area.Based on the findings,wetherefore recommend that antimicrobial agents should be inspected for acceptable activity beforethey are prescribed and administered empirically.Further study with a better design and surveyof antimicrobial susceptibility at large scale shoule be performed to draw advanced information.

Maternal delays in utilizing institutional delivery services, Bahir Dar, Ethiopia

Introduction: Timely referrals and access to appropriate health care had a great impact on reduction to maternal deaths and disabilities. Maternal delay is one of the contributing factors for high maternal mortality in developing countries. Maternal delays were categorized into three levels: delay in making the decision for seeking care, delay in arrival at a health facility, and delay in receiving adequate treatment. They have been named first, second, and third delay maternal delays;respectively. This study was aimed at assessing maternal delays in utilizing institutional delivery service sin Bahir Dar, North-Western Ethiopia. Methods: A cross sectional facility based study was conducted on a sample of 422 women attending at a public health facility for delivery services. The sample size was determined by using single population proportion formula and the study participants were selected by using a systematic random sampling method. Data were collected by means of a pre-tested, standardized questionnaire;analysis was carried out using SPSS version 16. Results: Data was collected from 410 laboring mothers. First delay, 155 (37.8%) of mothers was delayed in decision making for seeking care from the public health facility and the mean delay was 8 hours. Delay in seeking emergency obstetric care [EOC] was about seven fold among illiterate mothers (AOR, 6.71;95%CI, 3.66 -12.29) than literate mothers;the odds of delay for EOC were three times more likely among mother were unable to make decisions by their own (AOR, 3.30;95%CI, 1.25 -7.20) than those mothers who made the decisions of their own. Unemployed mothers were 4 times more likely to have the maternal delay in seeking EOC (AOR, 3.94;95%CI, 2.36 -6.57) than employed mothers. Second delay, 130 (31.7%) of mothers had transportation problems in reaching health care facilities. Predictors in the first maternal delay were also the major contributing factors for this delay. The third delay, after their arrival at health facilities, 126 (30.7%) mothers reported that they did not get the services on time;the mean waiting time for getting the service was 4 hours. Conclusions: Many mothers were not getting institutional delivery care services in a timely manner, due to the “three maternal delays”. Mothers’ literacy, decision making power and employment status were the main predictors for delivery service utilization. Hence, emphasis should be given for awareness creation on the risks of maternal delays, designing income generating mechanism, women empowering for in decision making and ambulance services should be strengthened.

Evaluations of the Characteristics of the Tropo-Strato-Mesopause Height and Temperature Variability over Bahir Dar,Ethiopia(11.60 N,37.30 E)Using SABER

The height profile of atmospheric temperature data between 12 km and 100 km was obtained from SABER/TIMED satellite instruments during the year 2016 and used to characterize the three atmospheric pauses temporal variability of height and temperature over Bahir Dar,Ethiopia(11.60 N,37.30 E).The daily,monthly,and frequency distributions of tropopause-stratopause-mesopause height and temperature are investigated.From the frequency distribution,we had found that of the tropopause-stratopause-mesopause height 17 km,48 km,and 98 km with the corresponding temperature 192 K,268 K,and 148 K.The decrement(cooling)trend lines of tropopause height 0.7 K/year and its corresponding tropopause increment temperature has been~1.5 K/year.The stratopause and mesopause trend lines of height are insignificant and the corresponding decrement(cooling)temperatures are~3 K/year and~13 K/year respectively.The mean monthly maximum heights of tropopause 19 km in May with a corresponding maximum temperature of 201 K in September.The maximum stratopause height 49.5 km in February and July and its temperature 268 K and 267 K in February and April respectively.The maximum mesopause height 98 km,95 km,97 km in March,Jun,and November respectively,and its maximum temperature 196 K and 198 K in January and July respectively.

Prevalence of childhood illness and mothers’/caregivers’ care seeking behavior in Bahir Dar, Ethiopia: A descriptive community based cross sectional study

Introduction: In Ethiopia, even though there are great achievements in decreasing infant and child mortality from year 2000 to 2011, still children are suffering from diarrheal diseases, respiratory problems and malnutrition. This study was done to determine the prevalence of illnesses among under-five children and mothers’/caregivers’ care seeking behavior for childhood illnesses in Bahir Dar, Ethiopia. Methods: A community based cross-sectional study was done on a sample of 415 mothers/caregivers from April 15 to May 15, 2011. Three kebeles (the smallest administrative unit) from Bahir Dar were selected randomly. The sample was proportionally distributed to the selected kebeles according to their population size. To be eligible to participate in the study, mothers had to live in households that had children under five years of age. These households were selected by systematic sampling method. Mothers/caregivers were interviewed in their homes using a structured questionnaire that had been pre-tested. The collected data were analyzed using a computer program of SPSS version 20.0. Result and Conclusions: The overall two weeks prevalence of childhood illness that had one or more symptoms of disease was 110 (26.5%). The prevalence of the most commonly reported symptoms were diarrhea, fever, acute respiratory infection (ARI) and others 11.3%, 10%, 6.3% and 4.6% among children of under five years respectively. Eighty (72.7%) of mothers sought treatment from health care facilities for sick children. The main reasons for not seeking treatment from health care facilities as reported by mothers/caregivers were, 53.3% Illness was not serious, 26.7% lack of money and 13.3% did not see any benefit for such childhood illness. Hence there is a need for designing a tailored health message for mother/ caregivers about preventable childhood illness and treatment seeking by the local health extension workers and program planners.

Modern Contraceptive Use among Orthodox Christian and Muslim Women of Reproductive Age Group in Bahir Dar City, North West Ethiopia: Comparative Cross Sectional Study

Background: Mothers are dying as a result of abortion associated with preventable unintended pregnancy. The objective of this study was to compare the prevalence of Modern contraceptive use and associated factors among Muslim and orthodox Christian women of reproductive age group in Bahir Dar city. Methods: Comparative Cross-sectional study was carried out on 504 participants selected through Simple random sampling technique from the list of households. Data were collected through a pretested interviewer administered questionnaire. The data were analyzed using logistic regression model to determine odds ratio as a measure of strength off association. Result: The prevalence of modern contraceptive use was higher among Orthodox Christian women by 0.28: 95% for the difference (0.19, 0.36). While 63.9% orthodox Christian women were using modern contraceptives only 36.1% of Muslim women were using Modern contraceptive. Age, Religiosity and education level were found to have a statistical association for modern contraceptive use in Both Orthodox Christian and Muslim women (p value < 0.05). Conclusion: The prevalence of modern contraceptive use among Muslim women was found to significantly lower than that in Orthodox Christian. Recommendation: More efforts should be done to increase the number of Modern Contraceptive users, by focusing on awareness creation on Modern contraceptives with special emphasis on Muslims.

Prevalence and associated factors of sexual violence among private college female students in Bahir Dar city, North Western Ethiopia

Background: Despite the higher risk victimization of young women in Ethiopia, the prevalence of sexual violence and its determinants among college students were scarce, particularly in the study area. This study was undertaken to determine the prevalence and associated factors of sexual violence among female private college students in Bahir Dar city. Methods: A cross sectional study was conducted in April 2012 among 541 female college students in Bahir Dar city using multistage sampling technique. A pretested self-administered questionnaire was used. The data were analyzed in bivariate and multivariate logistic regression analysis with SPSS version 16 soft ware package. Result: The study revealed that the prevalence of sexual violence among female college students was 37.3%. Respondents whose childhood background from rural areas were more than four times likely to have had sexual violence (AOR = 4.51, 95%CI: 1.67 - 12.16). The odds of sexual violence were higher for those respondents who had a close friend who drank alcohol (AOR = 3.13, 95%CI: 1.09 - 8.97). Besides, respondents who had never discussed on reproductive health issues with their parents were more than four times likely to have had sexual violence (AOR = 4.36, 95%CI: 1.40 -13.56). Conclusion: This study shows that sexual violence among female college students is higher. Sexual violence is associated with certain variables such as rural childhood residence, having a close friend who drank alcohol, and not discussing reproductive issues with parents. Therefore, it is recommend ed that sexual violence needs due attention and remedial action from policy makers, college officials, parents, students and other concerned bodies.

Risky Sexual Behaviour among Big Construction Enterprise Workers;Bahir Dar City, Amhara Regional State, Northwest Ethiopia

Background: Risky sexual behaviors are the major factors in rising sexually transmitted infections among adolescents and young adults. In Ethiopia construction industry is on increasing and deriving young people from rural area to the cities. Therefore, the aim of this study was to determine the prevalence of risky sexual behaviour and factors associated with among construction workers. Methods: A cross sectional study was conducted in March 2012 among construction workers in Bahir Dar city. The analysis was carried out using SPSS version 16. The data were analyzed in bivariate and multivariate logistic regression. Result: The prevalence of risky sexual behavior among construction workers was 44.9%. Female workers were about four times more likely to have had risky sexual practices than males (AOR = 3.86, 95% CI: 2.34 - 6.37). Respondents whose educational level less than fourth grade were 12 times more likely to be engaged in risky sex than whose educational level tenth grade or more (AOR = 12.13, 95% CI: 1.84 - 79.78). Divorced individuals were about five times more likely to have had risky sexual activities than married individuals (AOR = 4.63, 95% CI: 1.32 - 16.12). Respondents whose first sexual commencement from 15 - 19 years were about three times more likely to have had risky sexual behavior than from 20 - 24 years (AOR = 2.89, 95% CI: 1.70 - 4.91). Besides, the odds of having risky sexual behaviour among construction workers who had sexual partner at the time of the study were about 0.6 times less likely to have had risky sexual behaviours than workers who did not have (AOR = 0.6, 95% CI: 0.38, 0.96). Conclusion: The prevalence of risky sexual behavior among construction workers was 44.9%. Variables such as sex, educational level, marital status, age at first sexual intercourse, presence of current sexual partner and casual sex were found to be independent predictors of risky sexual behaviour. Therefore, interventions targeting on these factors were recommended.

Utilization of Youth Reproductive Health Services and Associated Factors among High School Students in Bahir Dar, Amhara Regional State, Ethiopia

Introduction: Young people in Ethiopia face greater reproductive health risks than adults. Despite efforts that were made on youth to utilize reproductive health service, studies show that there is little information about the extent to which youth utilize available health services. For the proper planning of appropriate health services for youth, it is crucial to have knowledge on the pattern of their use and its associated factors. So this study was conducted from June to September 2013 to assess utilization of youth reproductive health and its associated factors among high school students in Bahir Dar town, Amhara region, Ethiopia, 2013. Methods: Institutional based cross-sectional study was conducted among High school student from June to September 2013. Multistage sampling technique was used to select the total of 818 study participants. Data were collected by means of a pretested standardized questionnaire;analysis was carried out using SPSS version 16. Crude and adjusted odds ratio with 95% confidence interval was calculated using binary logistic regression;p-value less than 0.05 was considered as statistically significant. Results: The study indicated that among 818 students, 480(58.7%) were females. The data indicates that, 32% of youth utilized youth reproductive health service. Barriers in utilizing reproductive health services, for 31% of the students were due to inconvenience hours and 28.5% were due to fear of being seen by parents or people whom they know. Among socio-demographic predictors, age and reproductive health problems showed a significant association with utilization of youth reproductive health services. Students with age 20-24 were 2.31 times more likely to utilize reproductive health service than age15-19 (AOR = 2.31, CI 95% (1.01, 5.28)). Similarly, students who had reproductive health problems were 1.54 times more likely to utilize reproductive health services than students who had no reproductive illness. Conclusions: The majority of youth were not utilizing reproductive health services. Age and reproductive health problems showed a significant association with utilization of youth reproductive health services.

Satisfaction of Chronic Illness Patients at Felege Hiwot Referral Hospital, Bahir Dar City, Northwest Ethiopia

Introduction: Patient satisfaction is a popular way of evaluating quality of health care given in health facilities. This study was done to assess the level of chronic illness Patients’ Satisfaction in Felege Hiwot Referral Hospital, Bahir Dar City, Ethiopia. Method: Cross-sectional study was conducted by involving 415 patients using systematic sampling method at Felege Hiwot referral hospital, Bahir Dar City, Ethiopia from 1st September, 2012 to 2nd November, 2012. Structured questionnaire was data collection tool. The questionnaire was prepared in English. It was translated to Amharic and back to English. Discrepancies in the translation were resolved by mutual agreement with the research team. Pre-testing was done prior to the actual data collection process on a sample of 20 respondents and modified accordingly. The study was approved by ethics review board of Bahir Dar University. The collected data were checked for completeness and consistency before being coded, entered and analyzed using SPSS version 19. Result: The overall level of satisfaction of chronic illness patients in this hospital was 242 (58.3%) which is lower as compared to other local studies in Ethiopia. More than 40% of the patients were not satisfied with the service. Conclusion and Recommendations: The current level of patients’ satisfaction in the hospital is totally unacceptable care for a referral hospital situated in the capital city of a region in which more than 20 million people reside. Therefore, there is a need to revisit care given to chronic illness patients, and appropriate strategy should be designed to address the lifelong care needs of patients with chronic illness in our set up.

Impacts of environmental conditions on woody plant diversity,structure and regeneration in forest patches of Guna Mountain:Este District,South Gondar Zone,Ethiopia

Environmental conditions determine woody plant life such as species diversity,structure and regeneration status.This research aimed to assess the impact of environmental conditions on woody plant species diversity,structure and regeneration in forest patches of Guna Mountain:the case of Este District,South Gondar Zone,north-west Ethiopia.A total of 71 square sample plots(400 m~2 each) were established at 10 transects laid in five forest patches of the study area to collect vegetation data including the abundance of species,height and diameter at breast height(DBH).Environmental data including available potassium,available phosphorus,cation exchange capacity,soil texture,electrical conductivity,soil acidity,total nitrogen,organic matter,organic carbon,sodium adsorption ratio,exchangeable sodium percentage,bulk density,aspect,elevation,slope,latitude and longitude data were collected in the same plots.A correlation analysis between vegetation and environmental data was performed using rcorr(x) function in package Hmisc in R Programming Language.The most pronounced impacts were observed in altitude,grazing and pH,positively and silt,sand,electrical conductivity and cation exchange capacity,negatively.In addition,strong and significant impacts on plant structure were also observed due to the variation in soil texture and p H.The difference in aspect,sand and slope also impacted plant regeneration.The study showed that environmental parameters influence the diversity,structure and regeneration of woody plants.These parameters can be considered in the rehabilitation of the vegetation cover and conservation efforts of the rare woody species.Conservation measures that can minimalize the negative influences of environmental conditions can be applied through collaboration with communities around the forest patches.

Modeling urban land use dynamics using Markov-chain and cellular automata in Gondar City,Northwest Ethiopia

Modeling urban land-use dynamics is critical for urban experts’and infrastructure managers’planning.This study attempts to explore the land-use/land-cover(LULC)dynamics of Gondar using satellite images from 1984 to 2020.Markov-Chain and Cellular Automata(MC-CA)models have been recognized as performing well in predicting urban land-use change.However,only a few models work in Ethiopia in general,and no study in Gondar has applied this approach to study urban land-use patterns.Therefore,Gondar land-use/land cover changes of Gondar were predicted using the MC-CA model in IDRISI.The built-up area in Gondar city covered 1413 ha(3%of the total area)in 1984 and increased to 2380 ha(5%)in 1994;21153 ha(45.5%)in 2004;22622 ha(48.7%)in 2014;and 23427 ha(50.5%)in 2020.The area has been predicted to reach 57.5%in the 2050s,showing a faster increase that will cause a very vast loss of farmland.This will increase urban sprawl challenges as well as overall environmental disequilibrium in the preceding decade.Thus,innovative and careful structures and systems in urban planning are required to secure a sustainable urban future and to make our cities livable and competitive in the paradigm of sustainable cities.

Characterization and Performance of Magnesium Doped Bioactive Glass Nanoparticles

The bioactive glass and related biomaterials have become increasingly popular, and have also attracted the research interest of many researchers in recent years due its special performance and tissue engineering application. In this study, to create a material with a variety of properties Mg doped hollow bioactive glass (Mg-HBG) of 80SiO2-5P2O5-10CaO-5MgO system had been produced by using a sol-gel method. The porous structure nanoparticles were specifically made by employing the cetyltrimethylammonium bromide (CTAB) as a surfactant. Magnesium was selected as a doped material with HBG, because it is the most existing cations in the human body which helps for bone metabolism as well as it has antibacterial property. Based on different investigations resulted nanoparticle with the inclusion of the lower molar fractions magnesium has good tested result. For a drug model vancomycin hydrochloride (VAN) was used in this study and it has also good antibacterial activity effect. These findings help the possibility of using Mg-HBG nanoparticles to treat infectious bone abnormalities by demonstrating their compatibility with antibiotics, drug loading and release behavior.

The knowledge level of final year undergraduate health science students and medical interns about cardiopulmonary resuscitation at a university teaching hospital of Northwest Ethiopia

BACKGROUND: Cardiopulmonary resuscitation(CPR) is a life-saving technique which is used after cardiopulmonary arrest. Chance of survival after arrest will increase if it is coupled with sufficient knowledge. Final year undergraduate health science students and interns manage many trauma and critically ill patients in our hospital. Even though all students took CPR training in undergraduate course, we sometimes saw difficulties in the resuscitation of patients after cardiopulmonary arrest by undergraduate health professionals. This study was to assess the level of knowledge of undergraduate health science students and medical interns about cardiopulmonary resuscitation.METHODS: Hospital based cross-sectional study was conducted from February 1 to March 30, 2013. All undergraduate health professionals were included. The mean score of knowledge was compared for sex, original residence and department of the participants by using Student's t test and ANOVA with Scheffe's test. P values <0.05 were considered statistically significant.RESULTS: Four hundred sixty-one out of 506 students were included in this study with a response rate of 91.1%. The overall mean knowledge score of final year undergraduate health science students and interns was 11.1(SD=0.2). The mean knowledge scores of nurses, interns, health officer, midwifery, anesthesia and psychiatry nursing students were 9.84(SD=2.5), 13.34(SD=2.8), 9.81(SD=3.0), 8.77(SD=2.6), 13.31(SD=2.7) and 8.43(SD=2.4) respectively.CONCLUSIONS: The knowledge level of undergraduate health professionals about cardiopulmonary resuscitation was insufficient. Training about CPR for undergraduate health professionals should be emphasized.

Effect of Varieties and Fungicide Rate on Chocolate Spot (Botrytis fabae) Disease of Faba Bean (Vicia faba L.) at Tach Gayint District in South Gondar Zone, Amhara Region, Ethiopia

Faba bean is suffered with many biotic and abiotic factors. Chocolate spot disease, caused by Botrytis fabae is one of the biotic factors limiting yields of this crop resulting in yield losses up to 68% in Ethiopia. The experiment was conducted during 2020/2021 cropping season at Tach Gayint district, Ethiopia to determine the integration of faba bean varieties and fungicide rates on reducing chocolate spot disease. The experiment consisted of 12 treatments, viz. three faba bean varieties and four rate of Mancozeb fungicide in factorial arrangement. The experiment was laid out as randomized complete block design (RCBD) with three replications. Data was collected and analyzed. Results indicated that, disease incidence was reached at maximum percentage in all treatments on the last dates of assessment. But treatments were significantly difference in severity level. The least disease severity was recorded from varieties treated by 3.5 kg/ha of Mancozeb 80% WP with mean values Walki (12.7%), and (18.1% and 20.8%) on Gora and local variety respectively at the final dates of disease assessment. Similarly, the reduced AUDPC was also recorded from varieties treated by 3.5 kg/ha of Mancozeb 80% WP with mean values Walki (371.8% unit/day) and (539% and 686.4% days) on varieties Gora, and Local respectively. Whereas the maximum disease severity and AUDPC were obtained from unsprayed plots. Based on the results obtained, variety Walki treated with Mancozeb 80% WP at rate of 2.5 kg/ha and 3.5 kg/ha were effective to reduce the effect of chocolate spot disease for the study area.

Ethnobotanical Study of Wild Edible Plants and Their Indigenous Knowledge in Sedie Muja District, South Gondar Zone, Northwestern Ethiopia

Wild edible plants have played a vital role in supplementing the diet of people in developing countries. People in Sedie Muja District, South Gondar Zone, consume different parts of wild plants. This study was done in Sedie Muja District, South Gondar Zone to deal with ethnobotanical uses of selected wild edible plants. Field surveys were carried out in 2018-2019. Ethnobotanical data were collected from 84 respondents using semi-structured interview, guided field walk, market survey and field observations. Preference ranking, direct matrix ranking and informant consensus with buyers, sellers, cookers and elderly people of the user groups were used for data analysis. A total of 33 wild edible plants were documented. Of these families, Moraceae, Fabaceae and Solanaceae were the most dominant families that account 3 (11.5%) species each. Fruits are the most edible parts compared to the other edible plant parts that account 18 (54.5%). These species can be promoted for large-scale cultivation and marketing for the benefit of the local communities.

Oxidative exfoliation of spent cathode carbon:A two-in-one strategy for its decontamination and high-valued application

Spent cathode carbon(SCC)from aluminum electrolysis is a potential graphite resource.However,full use of the SCC remains a challenge,since it contains many hazardous substances(e.g.,fluoride salts,cyanides),encapsulated within the thick carbon layers and thus posing serious environmental concerns.This work presents a chemical oxidative exfoliation route to achieve the recycling of SCC and the decontaminated SCC with high-valued graphene oxide(GO)-like carbon structures(SCC-GO)is applied as an excellent adsorbent for organic pollutants.Specifically,after the oxidative exfoliation,the embedded hazardous constituents are fully exposed,facilitating their subsequent removal by aqueous leaching.Moreover,benefiting from the enhanced specific surface areas along with abundant O-containing functional groups,the as-produced SCC-GO,shows an adsorption capacity as high as 347 mg·g^(-1)when considering methylene blue as a pollutant model,which exceeds most of the recently reported carbon-based adsorbents.Our study provides a feasible solution for the efficient recycling of hazardous carbonaceous wastes.

Watershed prioritization for conservation planning using RUSLE and morphometric methods,Northwestern Ethiopia

Soil erosion and the subsequent sedimentation are serious environmental problems.Improper land management coupled with intense rainfall has complicated the problem in the Ethiopian highlands.Consequently,soil loss costs a profound amount of the national GDP and deters land productivity.Quantifying soil loss and prioritizing areas for conservation is imperative for proper planning and resource management.Therefore,this study aimed at estimating the mean annual soil loss rate of Gilgel Abay watershed which has critical implications on Lake Tana and Abbay River(Upper Blue Nile River),using RUSLE and morphometric analysis methods.Datasets including rainfall,soil,Digital Elevation Model and land use/land cover were used to generate important parameters required for the soil loss estimation.Data collected through field observation,consultation with experts and document analysis were used for validation purposes.The results of the study reveal that the watershed experienced an average soil loss rate of 39.8 t ha^(-1)yr^(-1).Subsequently,nearly 25%(37,038 ha)of the watershed is threatened by moderate to very severe soil loss.Among the four sub watersheds,sub watershed 3(S3)and sub watershed 4(S4),which consist of about 65%(105,000 ha)of the total area of the study watershed,experienced an annual soil loss rate of over 30 t ha^(-1)yr^(-1).The amount of soil loss that the study watershed has experienced is above the soil loss tolerance level of Ethiopia(2-18 t ha^(-1)yr^(-1))and the tropical region(10 t ha^(-1)yr^(-1)).Similarly,the results of morphometric analysis showed that the studied watershed has S-shaped hypsometric curve,an indication for maturity stage of landscape development.The studied watershed is also characterized by a non-circular shaped drainage with rugged and dissected topography that contributes to high flash flood,peak discharge and incidence of soil loss.The result of both models signified that S3 and S4 are highly susceptible to soil erosion.Therefore,these two sub watersheds need priority for soil and water conservation(SWC)measures.Furthermore,the study demonstrated the importance of the integration of different models in the identification of soil erosion prone areas and prioritization for the proper implementation of SWC measures.

Tree-based ecosystem services supply and multifunctionality of church forests and their agricultural matrix near Lake Tana,Ethiopia

Ecosystem services(ES)are the connection between nature and society,and are essential for the well-being of local communities that depend on them.In Ethiopia,church forests and the surrounding agricultural matrix supply numerous ES.However,the ES delivered by both land use types have not yet been assessed simultaneously.Here we surveyed both church forests and their agricultural matrices,aiming to quantify,compare and unravel the drivers underlying tree-based ES supply,density and multifunctionality.We found that almost all church forests and half of the agricultural matrices provided high ES densities.ES multifunctionality was higher in the agricultural matrices,suggesting that people deliberately conserve or plant multifunctional tree species.Furthermore,the supply of all categories of ES was positively correlated with church forest age(p-value<0.001)in the agricultural matrix,while the extent of church forest was positively correlated with the density of all categories ecosystem services score in the church forests(p-value<0.001).Our results can be used to prioritize conservation efforts at sites that provide high levels of ES supply,ES density and ES multifunctionality,and to prioritize restoration efforts at sites with low levels thereof.

Petrogenesis of Oligocene volcanic rocks of the Lake Tana area,Ethiopian large Igneous Province

The Lake Tana area is located within a complex volcano-tectonic basin on the northwestern Ethiopian plateau.The basin is underlain by a thick succession of Oligocene transitional basalts and sub-alkaline rhyolites overlain in places,particularly south of the lake,by Quaternary alkaline to mildly transitional basalts,and dotted with Oligo-Miocene trachyte domes and plugs.This paper presents the results of integrated field,petrographic,and major and trace element geochemical studies of the Lake Tana area volcanic rocks,with particular emphasis on the Oligocene basalts and rhyolites.The studies reveal a clear petrogenetic link between the Oligocene basalts and rhyolites.The Oligocene basalts are:(1)plagioclase,olivine,and/or pyroxene phyric;(2)show an overall decreasing trend in MgO,Fe_(2)O_(3),and CaO with silica;(3)have relatively low Mg#,Ni and Cr contents and high Nb/La and Nb/Yb ratios;and(4)show LREE enriched and generally flat HREE patterns.All these imply the origin of the Oligocene basalts by shallow-level fractional crystallization of an enriched magma sourced at the asthenospheric mantle.The Oligocene rhyolites:(1)are enriched in incompatible while depleted in compatible trace elements,P and Ti;(2)show a strong negative Eu anomaly;(3)contain appreciable amounts of plagioclase,apatite,and Fe-Ti oxides;and(4)show clear geochemical similarity with well-constrained rhyolites from the Large Igneous Province(LIP)of the northwestern Ethiopian plateau.Low-pressure fractional crystallization of mantle-derived basaltic magma in crustal magma chambers explains the origin of these rhyolites.Our study further shows that the Oligocene basalts and rhyolites are co-genetic and the felsic rocks of the Lake Tana area are related differentiates of the flood basalt volcanism in the northwestern Ethiopian plateau.

狄斯瓦螨对意大利蜜蜂工蜂呼吸代谢的影响

【目的】意大利蜜蜂Apis mellifera ligustica(简称“意蜂”)是世界重要的授粉昆虫,对维持生态平衡、提高农产品产量和保障粮食安全至关重要。但受狄斯瓦螨Varroa destructor侵害,全世界的意蜂蜂群每年都受到巨大损失。本研究主要探讨狄斯瓦螨对意蜂工蜂呼吸代谢的影响,为今后深入研究狄斯瓦螨与意蜂之间的相互作用奠定基础。【方法】应用SSI多通道昆虫呼吸仪测定感染狄斯瓦螨意蜂与健康意蜂不同发育阶段(4日龄幼虫、5日龄蛹、新出房成蜂和6日龄成蜂)工蜂的耗氧量、CO 2释放量和呼吸商,并分析其变化特征;同时采用实时荧光定量PCR(RT-qPCR)方法分析狄斯瓦螨感染意蜂与健康意蜂成年工蜂中呼吸代谢相关基因(Coq7,COXⅠ,CytB,CytC和IF-2 mt)的表达量变化。【结果】受狄斯瓦螨侵染后,意蜂工蜂耗氧量、CO 2释放量呈现出先上升后下降的趋势,其中耗氧量从5日龄蛹期的0.0244 mL/min下降至6日龄成蜂期的0.0093 mL/min;CO 2释放量从5日龄蛹期的0.0174 mL/min下降至6日龄成蜂期的0.0040 mL/min,极显著低于同龄期健康意蜂工蜂的。健康意蜂工蜂呼吸商随其生长过程逐渐增加,至6日龄成蜂时呼吸商最高,达0.9169;而狄斯瓦螨感染意蜂工蜂呼吸商则呈下降趋势,6日龄成蜂时呼吸商最低,为0.4424,显著低于同龄期健康成年工蜂的。实时荧光定量PCR结果发现,狄斯瓦螨感染意蜂成年工蜂中CytB和CytC基因的相对表达量分别是健康意蜂成年工蜂的1.7676和1.9929倍,差异显著。【结论】狄斯瓦螨侵染可直接影响意蜂工蜂的呼吸代谢,导致其正常代谢途径发生紊乱,严重破坏蜂群正常生长发育。