Appropriateness of Amikacin Dose Prescription, Monitoring and Safety during Hospitalization as an Impact of Clinical Pharmacologist Intervention, in the Israeli Regional Hospital

Background: Use of inappropriate amikacin dose is one of the most important factors in inducing toxicity, prolonged hospitalization as well as in increasing patient’s mortality. Objective: The aims of this study are the analysis of amikacin dose, serum level and the examination of the effectiveness of the clinical pharmacologist (CP) therapeutic drug monitoring (TDM) intervention to guarantee the safety of amikacin use. Methods: This is a one-year retrospective observational chart review study, which evaluates amikacin dose, serum drug level, development of adverse effects in patients on amikacin with or without CP TDM consultation. Results: Amikacin was prescribed for 393 complex patients, with median age 83. Amikacin group (AG) included 140 (32%) courses with CP consultation (AG1) and 292 (68%) courses without CP consultation (AG2). The distribution of most study characteristics in both groups was similar including amikacin dose (9-10 mg/kg/day), renal failure (14%) and mortality (12%). Acceptance for CP consultation was in 46% of amikacin courses and dose changes were done in 63% after CP intervention. Prolonged antibiotic course (4.6 ± 1.5 vs 3.8 ± 1.6 days, p < 0.0001) and the patient’s hemodynamic instability (15% vs 7%, p = 0.01) were more frequent in the AG1 compared to the AG2. There was a strong association between CP consultation and prolonged hospitalization (p = 0.005), while no association between it and amikacin adverse effects, renal failure or mortality. Conclusions: There was no trend to reducing amikacin toxicity, days of hospitaliza tion or mortality in patients with CP consultation. CP TDM intervention was more in the management of complicated clinical situations. However, it is necessary to optimize it.

Examination of the Appropriateness of Teaching Materials for Preventing Dangers during Ablution and Bathing of Infants by Mothers and Family Members

Purpose: This study aimed to develop teaching materials to prevent the dangers of ablution and bathing infants, based on the dangerous experiences of mothers and family members, and examine their appropriateness. Methods: A total of 20 midwives and public health nurses were selected as participants. Teaching materials and anonymous self-administered questionnaires were distributed, and the participants were asked to view the teaching materials and fill in the questionnaires. Retrieval was done by mail. The teaching materials included digital content, such as videos, sounds, and characters, which incorporated dangerous situations, preventions, and innovations in ablution and bathing procedures. The analysis was conducted by simple tabulation for each survey item. The free description was coded to preserve anonymity. This study was conducted with the approval of the Research Ethics Review Board of the authors’ affiliated university. Results: The teaching materials were found to be appropriate in terms of suitability to purpose, degree of difficulty of content, ease of viewing the videos, validity of time, appropriateness of expression, and usability. Conclusions: Ablution teaching materials that are used at the present time do not focus on dangers, and to date, no resources on bathing have been used as teaching materials. The created teaching materials in this study can be viewed multiple times, and mothers and family members who are unfamiliar with ablution and bathing can acquire knowledge regarding dangers and danger prevention. The addition of specific preventive measures and countermeasures for the occurrence of danger, along with practice, would result in the development of further appropriate teaching materials to reduce danger and alleviate anxiety.

二分图中高效计算top-n maximalα-biclique的方法研究

针对当二分图中一类节点的数量固定时,如何搜索另一类型节点数量排序为前n的maximalα-biclique的问题,提出了一种基础搜索算法和一种基于共同邻居概念的改进搜索算法。在使用(1,α)-core剪枝方法加快搜索的算法基础上,基于共同邻居搜索算法使用共同邻居的概念对算法进行了改进,该算法只遍历节点的二跳邻居,并利用节点顺序和最小阈值提高搜索效率。实验结果表明,两种算法都可以有效且高效地搜索节点数量排名为前n的maximalα-biclique。与基础搜索算法相比,基于共同邻居搜索算法的搜索效率提升了80%,在实际应用场景中更具优势。

Spousal Involvement in the Workplace of Doctors: What Is Defined as Appropriate or Inappropriate

Background: Workers spend a significant amount of time in the workspace. Involvement of a spouse in a doctor’s workplace can take different forms and come with different intentions. Objectives: The survey aimed to determine the prevalence and extent of spousal involvement in physicians’ workplaces as well as the outcome of such involvement on doctor’ swell-being, productivity, and relationship with colleagues. Methods: This cross-sectional online survey on spousal involvement in the workplace of doctors was conducted among 83 responding doctors from July to August 2023. Results: Among the respondents, 60 (72.3%) had witnessed a doctor’s spouse being involved in the workplace. The most common reason for spousal involvement in the workplace was to protect the spouse from what they perceived as a threat 34 (54.0%). Spouse’s ignorance of boundaries in the workplace (OR: 6.09 (95% CI: 1.70, 21.79) P: 0.003) and exertion of control by the spouse (OR: 11.2 (95% CI: 2.26, 56.41) P: 0.002) were significantly associated with higher odds of inappropriate spousal involvement in the workplace, while expression of love for spouse with acts of kindness was significantly associated with a lowered odd of inappropriate spousal involvement (OR: 0.11 (95% CI: 0.03, 0.36) P: 0.0001). Conclusion: Spousal involvement in the workplace is relatively common. Ignorance of the boundaries of the workplace and exertion of control by the spouse were significant enablers of inappropriate spousal involvement in the workplace of doctors. The establishment of workplace policies that define the limits of spousal involvement in the doctor’s workplace can foster a healthy workspace environment, enhance doctors’ well-being, and improve patient care.

A Bitcoin Address Multi-Classification Mechanism Based on Bipartite Graph-Based Maximization Consensus

Bitcoin is widely used as the most classic electronic currency for various electronic services such as exchanges,gambling,marketplaces,and also scams such as high-yield investment projects.Identifying the services operated by a Bitcoin address can help determine the risk level of that address and build an alert model accordingly.Feature engineering can also be used to flesh out labeled addresses and to analyze the current state of Bitcoin in a small way.In this paper,we address the problem of identifying multiple classes of Bitcoin services,and for the poor classification of individual addresses that do not have significant features,we propose a Bitcoin address identification scheme based on joint multi-model prediction using the mapping relationship between addresses and entities.The innovation of the method is to(1)Extract as many valuable features as possible when an address is given to facilitate the multi-class service identification task.(2)Unlike the general supervised model approach,this paper proposes a joint prediction scheme for multiple learners based on address-entity mapping relationships.Specifically,after obtaining the overall features,the address classification and entity clustering tasks are performed separately,and the results are subjected to graph-basedmaximization consensus.The final result ismade to baseline the individual address classification results while satisfying the constraint of having similarly behaving entities as far as possible.By testing and evaluating over 26,000 Bitcoin addresses,our feature extraction method captures more useful features.In addition,the combined multi-learner model obtained results that exceeded the baseline classifier reaching an accuracy of 77.4%.

Quantized Decoders that Maximize Mutual Information for Polar Codes

In this paper,we innovatively associate the mutual information with the frame error rate(FER)performance and propose novel quantized decoders for polar codes.Based on the optimal quantizer of binary-input discrete memoryless channels(BDMCs),the proposed decoders quantize the virtual subchannels of polar codes to maximize mutual information(MMI)between source bits and quantized symbols.The nested structure of polar codes ensures that the MMI quantization can be implemented stage by stage.Simulation results show that the proposed MMI decoders with 4 quantization bits outperform the existing nonuniform quantized decoders that minimize mean-squared error(MMSE)with 4 quantization bits,and yield even better performance than uniform MMI quantized decoders with 5 quantization bits.Furthermore,the proposed 5-bit quantized MMI decoders approach the floating-point decoders with negligible performance loss.

Maximal operators of pseudo-differential operators with rough symbols

Consider a pseudo-differential operator T_(a)f(x)=∫_(R^(n))e^(ix,ζ)a(x,ζ)f(ζ)dζwhere the symbol a is in the rough Hormander class L^(∞)S_(ρ)^(m)with m∈R andρ∈[0,1].In this note,when 1≤p≤2,if n(ρ-1)/p and a∈L^(∞)S_(ρ)^(m),then for any f∈S(R^(n))and x∈R^(n),we prove that M(T_(a)f)(x)≤C(M(|f|^(p))(x))^(1/p) where M is the Hardy-Littlewood maximal operator.Our theorem improves the known results and the bound on m is sharp,in the sense that n(ρ-1)/p can not be replaced by a larger constant.

Sum-Rate Maximization in Active RIS-Assisted Multi-Antenna WPCN

In this paper,we propose an active reconfigurable intelligent surface(RIS)enabled hybrid relaying scheme for a multi-antenna wireless powered communication network(WPCN),where the active RIS is employed to assist both wireless energy transfer(WET)from the power station(PS)to energyconstrained users and wireless information transmission(WIT)from users to the receiving station(RS).For further performance enhancement,we propose to employ both transmit beamforming at the PS and receive beamforming at the RS.We formulate a sumrate maximization problem by jointly optimizing the RIS phase shifts and amplitude reflection coefficients for both the WET and the WIT,transmit and receive beamforming vectors,and network resource allocation.To solve this non-convex problem,we propose an efficient alternating optimization algorithm with the linear minimum mean squared error criterion,semidefinite relaxation(SDR)and successive convex approximation techniques.Specifically,the tightness of applying the SDR is proved.Simulation results demonstrate that our proposed scheme with 10 reflecting elements(REs)and 4 antennas can achieve 17.78%and 415.48%performance gains compared to the single-antenna scheme with 10 REs and passive RIS scheme with 100 REs,respectively.

Kinematic calibration under the expectation maximization framework for exoskeletal inertial motion capture system

This study presents a kinematic calibration method for exoskeletal inertial motion capture (EI-MoCap) system with considering the random colored noise such as gyroscopic drift.In this method, the geometric parameters are calibrated by the traditional calibration method at first. Then, in order to calibrate the parameters affected by the random colored noise, the expectation maximization (EM) algorithm is introduced. Through the use of geometric parameters calibrated by the traditional calibration method, the iterations under the EM framework are decreased and the efficiency of the proposed method on embedded system is improved. The performance of the proposed kinematic calibration method is compared to the traditional calibration method. Furthermore, the feasibility of the proposed method is verified on the EI-MoCap system. The simulation and experiment demonstrate that the motion capture precision is significantly improved by 16.79%and 7.16%respectively in comparison to the traditional calibration method.

MAXIMAL FUNCTION CHARACTERIZATIONS OF HARDY SPACES ASSOCIATED WITH BOTH NON-NEGATIVE SELF-ADJOINT OPERATORS SATISFYING GAUSSIAN ESTIMATES AND BALL QUASI-BANACH FUNCTION SPACES

Assume that L is a non-negative self-adjoint operator on L^(2)(ℝ^(n))with its heat kernels satisfying the so-called Gaussian upper bound estimate and that X is a ball quasi-Banach function space onℝ^(n) satisfying some mild assumptions.Let HX,L(ℝ^(n))be the Hardy space associated with both X and L,which is defined by the Lusin area function related to the semigroup generated by L.In this article,the authors establish various maximal function characterizations of the Hardy space HX,L(ℝ^(n))and then apply these characterizations to obtain the solvability of the related Cauchy problem.These results have a wide range of generality and,in particular,the specific spaces X to which these results can be applied include the weighted space,the variable space,the mixed-norm space,the Orlicz space,the Orlicz-slice space,and the Morrey space.Moreover,the obtained maximal function characterizations of the mixed-norm Hardy space,the Orlicz-slice Hardy space,and the Morrey-Hardy space associated with L are completely new.

Screening for Anti-tumor Activity of Fractions from Buddleja officinalis Maxim

[Objectives]The anti-tumor activity of fractions from Buddleja officinalis Maxim.by petroleum ether,ethyl acetate,n-butanol and water solvent was studied.[Methods]The ethanol extract from B.officinalis Maxim.was extracted and then concentrated with petroleum ether,ethyl acetate,n-butanol and water,respectively,and the extracts were obtained.The inhibitory effects of the four different fractions on the growth of three tumor cell lines in vitro were detected by CCK-8 method,and the median inhibitory concentration(IC 50 value)was calculated.[Results]The four fractions inhibited the growth of the three tumor cell lines in vitro,among which the n-butanol fraction had the best anti-tumor activity.The IC 50 values of the n-butanol fraction on human gastric cancer(SGC-7901),human breast cancer(MCF-7)and human liver cancer(BEL-7404)cell lines were 0.08,1.58 and 0.12 mg/mL,respectively.[Conclusions]Petroleum ether,ethyl acetate,n-butanol and water fractions from the ethanol extract of B.officinalis Maxim.had certain anti-tumor effects,and the n-butanol fraction had the best anti-tumor activity.

Determination of Total Flavonoids in Acanthopanax senticosus(Rupr. et Maxim.) Harms by Enzymolysis and Its Technological Optimization

In order to optimize the ultrasonic extraction technique for the total flavonoid of leaf yellows plus, the contents of 21 leaf yellows plus total flavonoid from four regions in Heilongjiang Province were comparatively analyzed. The ultrasonic extraction technology was optimized by Box-Behnken response surface method, and the total flavonoid content of 21 kinds of Acanthopanax senticosus(Rupr. et Maxim.) Harms from different producing areas were analyzed by cluster analysis. The optimal process conditions were determined as ultrasonic time 30 min, solid-liquid ratio 1 : 12 and ultrasonic power 250 W, and the average yield of the total flavonoid was 1.453 mg·g^ (-1). By optimizing the ultrasonic-assisted extraction method, the total flavonoid content from different producing areas was compared in the experiment, which provided certain data support for the optimization of the extraction process in the future and laid a certain theoretical foundation for the quality analysis of Chinese medicinal materials.

Ways to Develop College Students' Awareness of Appropriateness in Oral Communication

Appropriateness is very important in oral communication.By analyzing the problems in oral communication,this article puts forward some efficient ways to raise college students’awareness of appropriateness in oral communication.

Appropriateness of outpatient gastrointestinal endoscopy in a non-academic hospital

AIM:To assess the appropriate use and the diagnostic yield of upper gastrointestinal endoscopy and colonoscopy in this subgroup of patients.METHODS:In total,789 consecutive outpatients referred for gastrointestinal(GI) endoscopy [381 for esophagogastroduodenoscopy(EGD) and 408 for colonoscopy] were prospectively enrolled in the study.The American Society for Gastrointestinal Endoscopy(ASGE) guidelines were used to assess the relationship between appropriateness and the presence of relevant endoscopic f indings.RESULTS:The overall inappropriate rate was 13.3%.The indications for EGD and colonoscopy were,respectively,appropriate in 82.7% and 82.6% of the exams,uncertain in 5.8% and 2.4% and inappropriate in 11.5% and 15%.The diagnostic yield was signif icant higher forEGDs and colonoscopies judged appropriate and uncertain when compared with those considered inappropriate(EGD:36.6% vs 36.4% vs 11.4%,P = 0.004;Colonoscopy:24.3% vs 20.0% vs 3.3%,P = 0.001).Of the 25 malignant lesions detected,all but one was detected in exams judged appropriate or uncertain.CONCLUSION:This study shows a good adherence to ASGE guidelines by the referring physicians and a significant increase of the diagnostic yield in appropriate examinations,namely in detecting neoplastic lesions.It underscores the importance that the appropriateness of the indication assumes in assuring high-quality GI endoscopic procedures.

Utility, Appropriateness of Request and Report of Computed Tomography Scan for the Diagnosis of Paranasal Sinuses Pathologies in a Sub-Saharan Africa Urban Setting

Background: Computed tomography (CT) Scan is the imaging of choice for the diagnosis of sino nasal (SN) pathologies in sub-Saharan African setting. However, it is often requested by non experienced practitioners. We aimed to describe the utility and the appropriateness of CT Scan request forms and results in the diagnosis of SN pathologies. Method: We conducted a retrospective cross-sectional study in four health facilities in Yaoundé, Cameroun, from October 2018 to September 2019. All patients to whom SN CT Scan was performed were called for an appointment. After informed consent, data on the appropriateness and conformity of the request form were collected and compared to the guidelines of the French society of radiology. CT Scan results were also collected and the quality of the report was evaluated. Results: A total of 206 SN CT Scan request forms and reports were included, with a mean patient age of 37.7 ± 16.1 years. The request form was conformed to guidelines in 8.3% of cases and was found appropriate in 62.6% of cases. No CT Scan report had all the items required, and 159 (77.2%) reports were useful. The most common diagnosis in patients with abnormal results was chronic sinusitis (49.5%) and SN polyp or polyposis (19.4%). Conclusion: Most of SN CT Scan requested were appropriate and useful. However, the conformity of request forms and reports to the guidelines is low. Suggesting the need for capacity building for the diagnosis of SN pathologies especially for non specialists like general practitioners and nurses.

Appropriateness of indication and diagnostic yield of colonoscopy: First report based on the 2000 guidelines of the American Society for Gastrointestinal Endoscopy

AIM: To assess the appropriateness of referrals and to determine the diagnostic yield of colonoscopy according to the 2000 guidelines of the American Society for Gastrointestinal Endoscopy (ASGE).METHODS: A total of 736 consecutive patients (415males, 321 females; mean age 43.6±16.6 years)undergoing colonoscopy during October 2001-March2002 Were prospectively enrolled in the study. The 2000ASGE guidelines were used to assess the appropriateness of the indications for the procedure. Diagnostic yield was defined as the ratio between significant findings detected on colonoscopy and the total number of procedures performed for that indication.RESULTS: The large majority (64%) of patients had colonoscopy for an indication that was considered'generally indicated'; it was 'generally not indicated' for20%, and it was 'not listed' for 16% in the guidelines.The diagnostic yield of colonoscopy was highest for the 'generally indicated' (38%) followed by 'not listed'(13%) and 'generally not indicated' (5%) categories.In the multivariable analysis, the diagnostic yield was independently associated with the appropriateness of indication that was 'generally indicated' (odds ratio=12.3) and referrals by gastroenterologist (odds ratio = 1.9).CONCLUSION: There is a high likelihood of inappropriate referrals for colonoscopy in an open-access endoscopy system. The diagnostic yield of the procedure is dependent on the appropriateness of indication and referring physician's specialty. Certain indications 'not listed' in the guidelines have an intermediate diagnostic yield and further studies are required to evaluate whether they should be included in future revisions of the ASGE guidelines.

Appropriateness of Screening of Angiopathic Complications Prevention in Ambulatory Patients with Diabetes

Background: Preventive care of diabetic foot and eye complications is essential. However, data on the prevalence of and factors associated with screening of angiopathic complications in ambulatory patients with diabetes are very limited in Switzerland. We aimed to fill this gap of knowledge. Methods: Cross-sectional data on recommended preventive care using RAND’s criteria in a random sample of patients aged 50-80 years in 2005-2006. Participants were recruited from 4 Swiss university primary care settings (in Lausanne, Geneva, Zürich and Basel). Scores for general preventive care in patients with and without diabetes were calculated by using generalized estimating equation binomial models. Multivariate regression models were used to identify determinants of appropriateness of angiopathic complications prevention. The main outcome measure was appropriateness of screening for angiopathic complications based on the 2005 American Diabetes Association recommendations corresponding to the period of data collection. Results: Among the 1002 patients aged 50 - 80 years, 292 (29.1%) had diabetes (101/292 [34.6%] female, mean BMI 30.7 [SD 5.7]). Fifty-nine percent had appropriate preventive foot care and 55.8% had appropriate preventive eye care. Only 34.6% had appropriate preventive care of both foot and eye. No differences in aggregate scores for general preventive care in patients with and without diabetes were found (67.5% vs. 69.1%, p value 0.39). In multivariate model, obesity was negatively (OR = 0.28, 0.15 - 0.53) and hyperlipidemia positively (OR = 2.29, 1.20 - 4.38) associated with appropriate eye preventive care and with appropriate combined foot and eye preventive care (OR = 0.35, 0.18 - 0.70 for obesity and OR = 2.82, 1.24 - 6.40 for hyperlipidemia). Conclusions: Preventive care of diabetic angiopathic complications is low among ambulatory patients despite universal health care coverage. Particular attention should be paid to obese patients with diabetes.

Improving the Appropriateness of Antipsychotic Prescribing for Behavioral and Psychological Symptoms of Dementia (BPSD): A Pilot Study of the Psychotropic Use Monitoring (PUM) Program

In nursing homes, antipsychotic prescribing decisions (APDs) for managing behavioral and psychological symptoms of dementia (BPSD) depend on the nursing staff’s feedback. Inappropriate APDs can result in the lack of timeliness, objectivity and important clinical information when nursing staff’s feedback on residents’ behavior and pharmacotherapy outcomes. Currently, there are no reported interventions for improving psychiatrists’ APDs through nursing staff’s monitoring and feedback processes. This one-group pre-and-post pilot study aimed to evaluate the feasibility and impact of implementing a newly-developed Psychotropic Use Monitoring (PUM) program for improving the appropriateness of APDs in a 50-bed dementia ward of a nursing home. The PUM intervention involved 16 pharmacist-trained nursing staff, who monitored and reported residents’ BPSD changes and psychotropic side effects for 24 weeks, while carrying out their routine care duties. A face-to-face interview was then administered to determine the nursing staff’s perceptions of PUM. Data of 51 residents were collected from hardcopy individual patient records to evaluate the changes in APDs and the number of resident falls before and after implementing PUM. The nursing staff reported increases in their knowledge, awareness, confidence, and actual frequency of monitoring for side effects, as well as their ability in differentiating and managing BPSD (p < 0.05). After PUM, there was a significant increase in the number of APDs due to side effect-related reasons (4 versus 16) (p < 0.031). Although not significant, the number of APDs with no documented reasons (5 versus 9) and the number of resident falls (7 versus 15) appeared to be lesser after PUM. This study demonstrated the nursing staff’s positive participation in PUM intervention, specifically in monitoring and feedback of side effects. Furthermore, a potential exists for PUM to encourage more judicious APDs, which may be useful in settings with heavy patient load, limited human resources and dependence on foreign nursing staff from differing cultural backgrounds.

Evaluation of Appropriateness of Proton Pump Inhibitors (PPIs) Use in the Region of Sharjah, United Arab Emirates (UAE)

Background: Proton pump inhibitors (PPIs) are drugs that reduce the production of acid in the stomach. Recently, the use of PPI has been increasing among communities, whether with or without prescription. As a part of the healthcare team, the pharmacist should not only dispense medications but also ensure the appropriate use of these medications. Studies conducted within 16 countries showed substantial variation in the appropriateness of the use of PPI drugs. Aim: To evaluate the appropriateness of PPIs use in Sharjah, UAE based on surveys answered by pharmacists, physicians, and patients. Methods: A cross-sectional survey study was conducted on December 2017 at Sharjah, UAE as an example of information obtained from the Middle East. Two different surveys were conducted on physicians and pharmacists. Both Physicians and Pharmacists were chosen randomly from Yellow Pages. The results obtained from both studies were used to develop a patient’s survey, which was distributed among University of Sharjah students, their families and random people at Shopping Malls and Clinics. Results: The results obtained from the patients’ survey showed that ~39% of PPI users from the region of Sharjah are 25 - 44 years old. Approximately 79% are using PPI according to physicians’ prescriptions. Prescriptions’ duration is varied between 1 month (39%) and 6 months (22%), where 52% of PPI users ask their physicians to prescribe PPIs when needed. Suggested reasons for the use of PPI included inappropriate food habits (52%), use of other medications (16%) or bacterial infection (13%). Around 52% of the patients did not receive any recommendations regarding the deprescribing of PPIs. According to the pharmacists’ surveys, an average sale of 5 - 10 PPI packages is reported per day, and around 50% are sold without a prescription. Most pharmacists were not fully aware of the health conditions and side effects of PPI drugs. On the other hand, physicians’ surveys showed that PPIs were mainly prescribed in the case of GERD and ulcer and for a maximum of 2 - 4 weeks. Approximately 75% of physicians recommend changing regimen by reducing the dose and stopping in case of chronic use of PPIs. Conclusion: The results from this survey study indicated that even though most PPI consumers at Sharjah, UAE are well aware of the use of PPI drugs and they follow the instructions given by the Physicians’, there is some discrepancy in the information obtained by the physicians, pharmacists, and patients. The reason for this discrepancy may be attributed to the missing role of the pharmacists which is currently just dispensing the medications without appropriate counseling. Thus the appropriate role of the pharmacists should be implemented according to the known international guidelines.

Pragmatic Distance and Appropriateness of Utterance Politeness

The Politeness Principle proposed by Leech complements Grice'Cooperative Principle to a certain extent in explaining the indirectness of language. However,the nature of politeness is its relativity.Determined by various factors such as social and cultural ones,the appropriateness of politeness at utterance level is affected by the appropriateness of the pragmatic distance between the participants. Different from the interpersonal relationships,pragmatic distance is calculated and determined in the process of communication varying with the variation of the communicative factors. Pragmatic distance is dynamic and can be maintained and altered by participants by using certain linguistic expressions to achieve the appropriateness of politeness in communication.