Probabilistic risk assessment of the environmental impacts of pesticides in the Crocodile (west) Marico catchment, North-West Province

External agricultural inputs, such as pesticides, may pose risks to aquatic ecosystems and affect aquatic populations, communities and ecosystems. To predict these risks, a tiered approach was followed, incorporating both the PRIMET and PERPEST models. The first-tier PRIMET model is designed to yield a relatively worst-case risk assessment requiring a minimum of input data, after which the effects of the risks can be refined using a higher tier PERPEST model. The risk assessment initially depends on data supplied from local landowners, pesticide characteristic, application scheme and physical scenario of the environment under question. Preliminary results are presented, together with ecotoxicological data on several frequently-used pesticides in a section of the Crocodile (west) Marico Water Management Area (WMA) in South Africa. This area is historically known to have a high pesticide usage, with deltamethrin, aldicarb, parathion, cypermethrin and dichlorvos being the main pesticides used. Deltamethrin was indicated as having the highest probability of risks to aquatic organisms occurring in the study area. Cypermethrin, parathion, dichlorvos, carbaryl, romoxynil, linuron, methomyl and aldicarb were all indicated as having possible risks (ETR 1-100) to the aquatic environment. Pesticides posing no risk included fenamiphos, abamectin, pendimethalin, captan, endosulfan, alachlor, bentazone and cyromazine (ET

Use of Cilostazol for Secondary Stroke Prevention: An Old Dog with New Tricks?

OBJECTIVE: To evaluate the safety and efficacy of cilostazol for secondary prevention of non-cardioembolic ischemic stroke. DATA SOURCES: PubMed and MEDLINE searches were performed (January 1970-September 2011) using the key words cilostazol, antiplatelet, aspirin, acetylsalicylic acid, secondary stroke prevention, ischemic stroke, intracerebral hemorrhage, intracranial, cerebrovascular accident, and transient ischemic attack. Additionally, reference citations from publications identified were reviewed. STUDY SELECTION AND DATA EXTRACTION: Articles published in English and relevant primary literature evaluating the efficacy and safety of cilostazol in the secondary prevention of atherosclerotic ischemic stroke were included. DATA SYNTHESIS: Antiplatelet therapy plays a vital role in the multifaceted approach to secondary stroke prevention. Current American Heart Association/American Stroke Association clinical guidelines for secondary stroke prevention support the use of aspirin, clopidogrel, and combination aspirin/extended-release dipyridamole. The antiplatelet, antithrombotic, and vasodilatory effects of cilostazol make it a potential alternative agent for atherosclerotic stroke prevention. Recent literature has demonstrated superior efficacy of cilostazol 100 mg twice daily for secondary stroke prevention compared to placebo and aspirin. Three clinical trials were reviewed (1 placebo-controlled, 2 aspirin-controlled), all of which were conducted in Japan or China. Cilostazol reduced the primary outcome of recurrence of stroke, with significantly fewer major bleeding events when compared to aspirin. CONCLUSIONS: Available literature suggests that cilostazol may be safer and more effective than aspirin in the secondary prevention of stroke in Asian patients. Further large-scale studies in more heterogeneous study populations are warranted to determine whether cilostazol is a viable therapeutic option for patients with a history of non-cardioembolic ischemic stroke

Guidance and Ethical Considerations for Undertaking Transgender Health Research and Institutional Review Boards Adjudicating this Research

The purpose of this review is to create a set of provisional criteria for Institutional Review Boards (IRBs) to refer to when assessing the ethical orientation of transgender health research proposals. We began by searching for literature on this topic using databases and the reference lists of key articles, resulting in a preliminary set of criteria. We then collaborated to develop the following nine guidelines: (1) Whenever possible, research should be grounded, from inception to dissemination, in a meaningful collaboration with community stakeholders; (2) language and framing of transgender health research should be non-stigmatizing; (3) research should be disseminated back to the community; (4) the diversity of the transgender and gender diverse (TGGD) community should be accurately reflected and sensitively reflected; (5) informed consent must be meaningful, without coercion or undue influence; (6) the protection of participant confidentiality should be paramount; (7) alternative consent procedures should be considered for TGGD minors; (8) research should align with current professional standards that refute conversion, reorientation, or reparative therapy; and (9) IRBs should guard against the temptation to avoid, limit, or delay research on this subject

An evidence-based model for understanding transgender mental health in Australia

This is an electronic version of an article published in "Riggs, D.W. Ansara, Y.G., & Treharne, G.J. (2015). An evidence-based model for understanding transgender mental health in Australia. Australian Psychologist, 50, 32-39". Author version made available with the publisher's permission no earlier than January 2016A growing body of empirical research has documented the mental health experiences of Australian transgender people. This research indicates three key factors that appear to play a role in determining outcomes for adult transgender Australians: 1) discrimination, 2) access to hormones and/or surgery, 3) community connectedness. Two theoretical frameworks clarify why these factors exist and how they can lead to either negative or positive mental health outcomes. The first is cisgenderism, which describes the ideology that delegitimizes people’s own understanding of their genders and bodies. Although anyone can experience cisgenderism, it is a particularly common experience for transgender people. The second is decompensation, which describes the processes through which the cumulative effects of stressors may lead to poor mental health. Drawing on both previous empirical findings and these two theoretical frameworks, this paper proposes, and provides initial testing of, a model for understanding the mental health of transgender adults in Australia. The paper concludes by suggesting the need for changes regarding how decisions are made about mental health service provision for transgender people, how mental health professionals understand the lives of transgender people, and how legislation can better ensure the full inclusion of transgender people in Australia

Assessment techniques, database design and software facilities for thermodynamics and diffusion

The purpose of this article is to give a set of recommendations to producers of assessed thermodynamic data, who may be involved in either the critical evaluation of limited chemical systems or the creation and dissemination of larger thermodynamic databases. Also, it is hoped that reviewers and editors of scientific publications in this field will find some of the information useful. Good practice in the assessment process is essential, particularly as datasets from many different sources may be combined together into a single database. With this in mind, we highlight some problems that can arise during the assessment process and we propose a quality assurance procedure. It is worth mentioning at this point, that the provision of reliable assessed thermodynamic data relies heavily on the availability of high quality experimental information. The different software packages for thermodynamics and diffusion are described here only briefly

Thermodynamic properties of binary HCP solution phases from special quasirandom structures

Three different special quasirandom structures (SQS) of the substitutional hcp $A_{1-x}B_x$ binary random solutions ($x=0.25$, 0.5, and 0.75) are presented. These structures are able to mimic the most important pair and multi-site correlation functions corresponding to perfectly random hcp solutions at those compositions. Due to the relatively small size of the generated structures, they can be used to calculate the properties of random hcp alloys via first-principles methods. The structures are relaxed in order to find their lowest energy configurations at each composition. In some cases, it was found that full relaxation resulted in complete loss of their parental symmetry as hcp so geometry optimizations in which no local relaxations are allowed were also performed. In general, the first-principles results for the seven binary systems (Cd-Mg, Mg-Zr, Al-Mg, Mo-Ru, Hf-Ti, Hf-Zr, and Ti-Zr) show good agreement with both formation enthalpy and lattice parameters measurements from experiments. It is concluded that the SQS's presented in this work can be widely used to study the behavior of random hcp solutions.Comment: 15 pages, 8 figure

Aspirin Dosing for the Prevention and Treatment of Ischemic Stroke: An Indication-Specific Review of the Literature

OBJECTIVE: To evaluate the efficacy of aspirin for the treatment and prevention of ischemic stroke and identify the minimum dose proven to be effective for each indication. DATA SOURCES: PubMed and MEDLINE searches (January 2009–January 2010) were performed to identify primary literature, using search terms including aspirin, stroke prevention, acute ischemic stroke, acetylsalicylic acid, atrial fibrillation, myocardial infarction, and carotid endarterectomy. Additionally, reference citations from publications identified were reviewed. STUDY SELECTION AND DATA EXTRACTION: Articles published in English were evaluated and relevant primary literature evaluating the efficacy of aspirin in the prevention of stroke was included in this review. DATA SYNTHESIS: Antiplatelet therapy is the benchmark for the prevention of ischemic stroke. Aspirin has been proven to prevent ischemic stroke in a variety of settings. Despite the frequency at which aspirin continues to be prescribed in patients at risk of ischemic stroke, there remains confusion in clinical practice as to what minimum dose is required in various at-risk patients. A thorough review of the primary literature suggests that low-dose (50–81 mg daily) aspirin is insufficient for some indications. Acute ischemic stroke treatment requires 160–325 mg, while atrial fibrillation and carotid arterial disease require daily doses of 325 and 81–325 mg, respectively. CONCLUSIONS: Available evidence suggests that aspirin dosing must be individualized according to indication. Recommendations provided by national guidelines at times recommend lower doses of aspirin than have been proven effective. Higher doses are indicated for stroke prevention in atrial fibrillation (325mg) and acute ischemic stroke patients (160–325 mg). Aspirin has not yet been proven effective for primary prevention of strokes in men, and a minimum dose for these patients cannot be determined from the available data

Compilation and critical analysis of thermodynamic data for ternary alloy systems

The thermodynamic approach in resolving industrial problems concerned with high temperature has led, in the two last decades, to a notable development of both theoretical and experimental studies on multicomponent system. Phase diagram determinations of metallic systems are still carried out very extensively because of their importance in the field of material science, mainly in steelmaking, non-ferrous metallurgy, crystal growth, electroslag- refining, nuclear materials, etc..

Drug Therapy Vs. Ablation Therapy for Patients with Atrial Fibrillation

The prevalence of atrial fibrillation is 6.5 percent in the adult population in the United States, in an attempt to treat this patient population, there are numerous options and this study attempts to find the optimal treatment plan that has the least Atrial fibrillation(AF) reoccurrence, best quality of life and is the most effective. This is a Systematic Review comparing catheter ablation therapy vs. drug therapy in treating patients with atrial fibrillation. The search engines used in this analysis include PubMed, UpToDate, Google Scholar and Academic Search Premier. A total of 19 articles were analyzed and data was extracted, and conclusions were made. This review came to three conclusions, Anti-arrhythmic drugs (AAD) had no statistical significance over rate control 2,7,19 but specifically amiodarone had poorer side effects and more hospitalizations 3,7,19. Secondly, catheter ablation therapy was more effective than drug therapy, specifically with multiple procedures and concomitant AAD use in reducing AF reoccurrence and improving quality of life 12,13 . Thirdly, catheter ablation therapy was associated with serious adverse effects such as cardiac tamponade and a 4.7 % increased risk for stroke9 . Keeping this in mind, Amiodarone showed to have an increased risk of stroke by 1.8-fold 2,3, and an increased mortality p=0.0082,19 . AAD therapy has limited use because of the toxic side effects, therefore catheter ablation therapy serves as a promising long-term solution. There should be continued improved efforts towards advancing and optimizing the ablation therapy technique. Patients who fit the characteristics of more likely to succeed should be offered ablation therapy as first line treatment, and additional procedures should be offered until complete cessation of AF

Relationship between casting modulus and grain size in cast A356 aluminium alloys

Microstructure of Al-Si alloy castings depends most generally on melt preparation and on the cooling rate imposed by the thermal modulus of the component. In the case of Al-Si alloys, emphasis is put during melt preparation on refinement of pro-eutectic (Al) grains and on modification of the Al-Si eutectic. Thermal analysis has been used since long to check melt preparation before casting, i.e. by analysis of the cooling curve during solidification of a sample cast in an instrumented cup. The conclusions drawn from such analysis are however valid for the particular cooling conditions of the cups. It thus appeared of interest to investigate how these conclusions could extrapolate to predict microstructure in complicated cast parts showing local changes in the solidification conditions. For that purpose, thermal analysis cups and instrumented sand and die castings with different thermal moduli and thus cooling rates have been made, and the whole set of cooling curves thus recorded has been analysed. A statistical analysis of the characteristic features of the cooling curves related to grain refinement in sand and die castings allowed determining the most significant parameters and expressing the cube of grain size as a polynomial of these parameters. After introduction of a further parameter quantifying melt refining an excellent correlation, with a R2 factor of 0.99 was obtained