Simple Study Design Research Articles

Patient experiences of randomised placebo-controlled trial participation during end-of-life palliative cancer care

BackgroundPerforming clinical trials in palliative cancer care is known to be challenging.ObjectiveThis study aimed to explore how patients with advanced cancer experienced their participation in a randomised, placebo-controlled trial while...

Enhanced study design for acute inhalation studies with hydrophobic surface-treated particles to determine toxicological effects including suffocation

High concentrations of low-density particles may cause effects in acute inhalation toxicity studies which can be easily underestimated or misinterpreted following strictly the OECD TG 436, i.e., limited parameters as mortality and gross lesions will be evaluated only. Seven particle types (synthetic amorphous silica (SAS) HMDZ-SAS, silica gel, pyrogenic SAS, and precipitated SAS, calcium carbonate, aluminum oxide pyrogenic alumina, organic red pigment) were chosen at the highest technically feasible concentration of approximately 500 mg/m3 for acute inhalation studies with an expanded endpoint setup. Therefore additional parameters and a thorough histopathological evaluation of an extensive set of organs, including the respiratory tract emphasizing the nasal cavities were added. Six Crl:WI rats per study were exposed for four hours from which three animals were sacrificed after 24 hours and three animals after 14 days. HMDZ-SAS caused early death in all animals due to blockage of the nasal passages caused by its hydrophobicity. For all other Si-containing compounds, histology revealed minor inflammatory and reactive lesions in lungs after 24 hours that were still present after 14 days, except in silica gel-treated animals. After 14 days, for pyrogenic SAS, precipitated SAS, and pyrogenic alumina, granulomas formed in the BALT and lung-associated lymph nodes. In contrast, the calcium carbonate induced almost no findings, and the red pigment (also tested for the additional dose of 1000 mg/m3) stuck partially to the nasal mucosa without causing pathological damage and partly entered the lungs without showing any adverse effects. The results of the present study highlight the advantage of improving the rather simple study design of acute inhalation studies by implementing an extended study design.

The Subchronic Effect Of Water Extract Leaves Ofsoursop (Annona Muricata L.) Bax Expression Of Neuron Rat Hippocampus Gyrus Dentatus (Rattus Norvegicus)

Soursop (Annona muricata) is a plant that is rich in benefits and widely used in the community as one of the traditional medicines. Annona muricata itself contains a compound known as acetogenin toxic if consumed continuously, In addition to the benefits so many of Annona muricata can give side effects to the body one of which is the part of the brain is called the gyrus dentatus. Anonaine, compound acetogenin could induce Bax expression in cancer cells resulting in apoptosis. This study wanted to find out if Annona muricata can induce Bax expression of neuron hippocampus gyrus dentatus female rats (rattus nervous). The purpose of this study was to subchronic effect of aqueous extract of soursop leaves (Annona muricata L.) Bax expression of neuron rat hippocampus gyrus dentatus(Rattus norvegicus). This study was a simple experimental study design using a post-test control group design to see Bax expression of neuron rat hippocampus gyrus dentatus (Rattus norvegicus) in subchronic administration of aqueous extract of soursop leaves (Annona muricata L.). The subjects were adult female rats (Rattus norvegicus) that met the inclusion criteria. The samples were 10 rats. Subjects were divided into 2 groups and each group consisted of 5 rats.

Real World Data Studies of Antineoplastic Drugs: How Can They Be Improved to Steer Everyday Use in the Clinic?

There is a growing interest in real world evidence when developing antineoplastic drugs owing to the shorter length of time and low costs compared to randomised controlled trials. External validity of studies in the regulatory phase can be enhanced by complementing randomised controlled trials with real world evidence. Furthermore, the use of real world evidence ensures the inclusion of patients often excluded from randomised controlled trials such as the elderly, certain ethnicities or those from certain geographical areas. This review explores approaches in which real world data may be integrated with randomised controlled trials. One approach is by using big data, especially when investigating drugs in the antineoplastic setting. This can even inform artificial intelligence thus ensuring faster and more precise diagnosis and treatment decisions. Pragmatic trials also offer an approach to examine the effectiveness of novel antineoplastic drugs without evading the benefits of randomised controlled trials. A well-designed pragmatic trial would yield results with high external validity by employing a simple study design with a large sample size and diverse settings. Although randomised controlled trials can determine efficacy of antineoplastic drugs, effectiveness in the real world may differ. The need for pragmatic trials to help guide healthcare decision-making led to the development of trials within cohorts (TWICs). TWICs make use of cohorts to conduct multiple randomised controlled trials while maintaining characteristics of real world data in routine clinical practice. Although real world data is often affected by incomplete data and biases such as selection and unmeasured biases, the use of big data and pragmatic approaches can improve the use of real world data in the development of antineoplastic drugs that can in turn steer decision-making in clinical practice.

Distribution, Population Density, and Behavior of Dwarf Galagos (Paragalago sp.) in Taita Hills, Kenya

AbstractA good understanding of taxonomy, distribution, and population density is needed for conservation. Scientific knowledge of dwarf galagos (Paragalago sp.) remains limited. Two populations of Taita dwarf galagos survive in the largest remnants of moist montane forest in Taita Hills, Kenya. We obtained acoustic data on the two remaining populations using AudioMoths—small, passive recorders—more than 231 h in January and February 2021. We measured forest structure by using airborne LiDAR and ground-level observations and tested the influence of forest size and height, canopy coverage, and density on calls per hour as an indicator of population density. Forest size significantly affected population size. Taita dwarf galagos prefer dense canopy coverage, and they prefer the lower 20–30-m tall forest. Mbololo forest (185 ha) has steady population, whereas dwarf galagos are nearly extinct in Ngangao forest (120 ha). The calls of Taita dwarf galagos resemble those of Kenya coast dwarf galagos (Paragalago cocos). DNA studies are urgently needed to resolve the taxonomic status of both surviving populations of dwarf galagos in the Taita Hills. This simple study design should be conducted across African forests to obtain crucial knowledge for galago conservation.

Data quality in an HIV vaccine efficacy clinical trial in South Africa: through natural disasters and with discipline

BackgroundTo produce quality data that informs valid clinical trial results and withstands regulatory inspection, trial sites should adhere to many complex and dynamic requirements. Understanding non-conformance to requirements informs the emerging field of improvement science. We describe protocol deviations in South Africa’s largest HIV vaccine efficacy trial.MethodsWe analysed data from the HVTN 702 trial using mixed methods. We obtained descriptive statistics, from protocol deviation case report forms collected from 2016–2022, of deviation by participant, trial site, and time to site awareness. We thematically analysed text narratives of deviation descriptions, corrective and preventive actions, generating categories, codes and themes which emerged from the data.ResultsFor 5407 enrollments, 4074 protocol deviations were reported (75 [95% CI: 73.0–77.6] deviations per 100 enrolments). There was a median of 1 protocol deviation per participant (IQR 1–2). Median time from deviation to site awareness was 31 days (IQR 0–146). The most common category of deviation type was omitted data and/or procedures (69%), and 54% of these omissions were stated to have arisen because of the national lockdown at the beginning of the COVID-19 pandemic. The ratio of protocol deviations to cumulative enrolments was highest in the year 2020 (0.34). Major themes of deviations were: COVID-19 and climate disasters giving rise to deviation trends, subroutines introducing an opportunity for deviation, and document fragmentation (such as requirements dispersed across multiple guidance documents) as an obstacle. Preventive action categories were: no preventive measures; discipline, training and/or awareness; quality review, checking and verifying and changing the process and/or implementation tools. Major themes of preventive actions were that systems-based actions are unusual, with people-based actions dominating, and that root cause analysis was rarely mentioned.ConclusionsIn the age of infectious and climate disaster risks, trials may benefit from simple study designs and trial-related documents. To optimise protocol adherence, sponsors and sites should consider ongoing training, and routinely review deviation reports with a view to adjusting processes. These data quality lessons may inform future trial design, training and implementation.Trial registrationHVTN 702 was registered with the South African National Clinical Trials Register (DOH-27–0916-5327) and ClinicalTrials.gov (NCT02968849).

Statistical matching and subclassification with a continuous dose: Characterization, algorithm, and application to a health outcomes study

Subclassification and matching are often used in empirical studies to adjust for observed covariates; however, they are largely restricted to relatively simple study designs with a binary treatment and less developed for designs with a continuous exposure. Matching with exposure doses is particularly useful in instrumental variable designs and in understanding the dose-response relationships. In this article we propose two criteria for optimal subclassification based on subclass homogeneity, in the context of having a continuous exposure dose, and propose an efficient polynomial-time algorithm that is guaranteed to find an optimal subclassification with respect to one criterion and serves as a 2-approximation algorithm for the other criterion. We discuss how to incorporate dose and use appropriate penalties to control the number of subclasses in the design. Via extensive simulations, we systematically compare our proposed design to optimal nonbipartite pair matching and demonstrate that combining our proposed subclassification scheme with regression adjustment helps to reduce model dependence for parametric causal inference with a continuous dose. We apply the new design and associated randomization-based inferential procedure to study the effect of transesophageal echocardiography (TEE) monitoring during coronary artery bypass graft (CABG) surgery on patients’ postsurgery clinical outcomes, using Medicare and Medicaid claims data, and find evidence that TEE monitoring lowers patients’ all-cause 30-day mortality rate.

Less confident, successful and happy: patients with post-acne hyperpigmentation are stigmatized.

Stigmatization is a major issue for individuals with acne. Using a simple but expressive study design and a large sample representative of the German general population, this study showed that individuals with residual post-inflammatory hyperpigmentation (PIH) are stigmatized by the general population even in the absence of active lesions, prolonging the mental burden of acne. Considering that PIH can take years to fade, the results of this study underline the importance of preventing and treating PIH to reduce the mental burden for the affected individuals.

Importance of the Pneumococcus in Community-acquired Pneumonia in Tender-age Infants on the Background of Vaccination

«IMPORTANCE OF THE PNEUMOCOCCUS IN COMMUNITY-ACQUIRED PNEUMONIA IN TENDER-AGE INFANTS ON THE BACKGROUND OF VACCINATION»
 The authors of the manuscript provide data demonstrating that una pneumonia against the background of vaccination is accompanied by a change in the etiological structure. The article is a new idea and overall it is well written and structured.
 However, simple study design, lack of patient baseline and follow-up data limit the conclusion of withdrawal.
 I invite the authors to solve the following questions:
 1) There are many spelling, grammatical and punctuation errors. Authors should correct mistakes and rewrite the article in a clear and understandable style. I have visited the authors with the help of a language expert on rewriting.
 2) The main problem of the manuscript is poor statistical processing and statistical reporting. The authors stated: “All data were expressed as confidence intervals. Thus, it is unclear whether the etiological structure was normally distributed. Moreover, following normal scientific practice, authors should indicate specific statistical significance values ​​when comparing each test parameter.
 3) The cited literature is relevant to the research and meets the requirements of the journal. But mentions of 9/19 were published over 10 years ago. I recommend reading current research on this topic.
 In conclusion, the work makes a good impression. On the other hand, it can be published after significant changes with reference to the comments mentioned above, including bug fixes and rewriting of the article in a clear and easily understandable style.

Nicotine replacement treatment, e-cigarettes and an online behavioural intervention to reduce relapse in recent ex-smokers: a multinational four-arm RCT.

Relapse remains an unresolved issue in smoking cessation. Extended stop smoking medication use can help, but uptake is low and several behavioural relapse prevention interventions have been found to be ineffective. However, opportunistic 'emergency' use of fast-acting nicotine replacement treatment or electronic cigarettes may be more attractive and effective, and an online behavioural Structured Planning and Prompting Protocol has shown promise. The present trial aimed to evaluate the clinical effectiveness and cost-effectiveness of these two interventions. A randomised controlled trial. English stop smoking services and Australian quitlines, Australian social media and St Vincent's Hospital Melbourne, Fitzroy, VIC. Ex-smokers abstinent for at least 4 weeks, with some participants in Australia also recruited from 1 week post quit date. The planned sample size was 1400, but the trial was curtailed when 235 participants were recruited. Participants were randomised in permuted blocks of random sizes to (1) oral nicotine replacement treatment/electronic cigarettes to use if at risk of relapse, plus static text messages (n = 60), (2) the Structured Planning and Prompting Protocol and interactive text messages (n = 57), (3) oral nicotine replacement treatment/electronic cigarettes plus the Structured Planning and Prompting Protocol with interactive text messages (n = 58) or (4) usual care plus static text messages (n = 59). Owing to delays in study set-up and recruitment issues, the study was curtailed and the primary outcome was revised. The original objective was to determine whether or not the two interventions, together or separately, reduced relapse rates at 12 months compared with usual care. The revised primary objective was to determine whether or not number of interventions received (i.e. none, one or two) affects relapse rate at 6 months (not biochemically validated because of study curtailment). Relapse was defined as smoking on at least 7 consecutive days, or any smoking in the last month at final follow-up for both the original and curtailed outcomes. Participants with missing outcome data were included as smokers. Secondary outcomes included sustained abstinence (i.e. no more than five cigarettes smoked over the 6 months), nicotine product preferences (e.g. electronic cigarettes or nicotine replacement treatment) and Structured Planning and Prompting Protocol coping strategies used. Two substudies assessed reactions to interventions quantitatively and qualitatively. The trial statistician remained blinded until analysis was complete. The 6-month relapse rates were 60.0%, 43.5% and 49.2% in the usual-care arm, one-intervention arm and the two-intervention arm, respectively (p = 0.11). Sustained abstinence rates were 41.7%, 54.8% and 50.9%, respectively (p = 0.17). Electronic cigarettes were chosen more frequently than nicotine replacement treatment in Australia (71.1% vs. 29.0%; p = 0.001), but not in England (54.0% vs. 46.0%; p = 0.57). Of participants allocated to nicotine products, 23.1% were using them daily at 6 months. The online intervention received positive ratings from 63% of participants at 6 months, but the majority of participants (72%) completed one assessment only. Coping strategies taught in the Structured Planning and Prompting Protocol were used with similar frequency in all study arms, suggesting that these are strategies people had already acquired. Only one participant used the interactive texting, and interactive and static messages received virtually identical ratings. The inability to recruit sufficient participants resulted in a lack of power to detect clinically relevant differences. Self-reported abstinence was not biochemically validated in the curtailed trial, and the ecological momentary assessment substudy was perceived by some as an intervention. Recruiting recent ex-smokers into an interventional study proved problematic. Both interventions were well received and safe. Combining the interventions did not surpass the effects of each intervention alone. There was a trend in favour of single interventions reducing relapse, but it did not reach significance and there are reasons to interpret the trend with caution. Further studies of both interventions are warranted, using simpler study designs. Current Controlled Trials ISRCTN11111428. This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 68. See the NIHR Journals Library website for further project information. Funding was also provided by the National Health and Medical Research Council, Canberra, ACT, Australia (NHMRC APP1095880). Public Health England provided the funds to purchase the nicotine products in England.

Biomechanical properties of canine staphylectomies closed with barbed or smooth suture.

To compare the duration of closure and biomechanical properties of staphylectomies closed with absorbable bidirectional barbed suture or smooth monofilament suture in a simple continuous or interrupted pattern STUDY DESIGN: Ex vivo study SAMPLE POPULATION: Soft palates (n = 60) harvested from mesaticephalic canine cadavers METHODS: One centimeter of tissue was excised from the caudal border of each soft palate, and the oral and nasopharyngeal mucosal surfaces were apposed with 2-0 bidirectional Quill Monoderm knotless closure device barbed suture (Q), 3-0 Monocryl in a simple continuous (MC) pattern, or 3-0 Monocryl in a simple interrupted (MI) pattern (n = 20 per group). Duration of closure was compared between groups. Tissues were tested under tension to failure, and mode of failure data were collected by video capture. Closure time was longer for MI closures than for Q and MC closures, with means of 259.9, 215.4, and 196.7 seconds, respectively (P < .0001). No difference was detected in yield force, force to first tissue rupture, maximum force, and energy required for yield and maximum force between groups. Energy to yield was 190.0, 167.8, and 188.95 N-mm for MI, Q, and MC closures, respectively. Biomechanical properties of staphylectomies closed with barbed or smooth sutures did not differ in this cadaveric model. Barbed suture can be considered as an alternative for closure of canine staphylectomies. These results provide evidence to justify additional research to evaluate clinical outcomes in dogs undergoing staphylectomy.

SYNTHESIS, CHARACTERIZATION AND IN VIVO EVALUATION OF PH SENSITIVE HYDROXYPROPYL METHYL CELLULOSE-GRAFT-ACRYLIC ACID HYDROGELS FOR SUSTAINED DRUG RELEASE OF MODEL DRUG NICORANDIL

Background: Anti hypertensive drugs like “Nicorandil” require frequent dosing due to their shorter half-life. Such drugs are also pH sensitive, due to which greater portions of these drugs are degraded in acidic pH of stomach resulting in lesser bioavailability. The objective of this study was to formulate graft polymeric carrier system for sustained delivery of nicorandil to minimize dosing frequency and enhance patient compliance. Materials Methods: This animal model study was conducted in Department of Pharmacy, Islamia University of Bahawalpur, Pakistan. Hydroxypropyl methyl cellulose-graft-acrylic acid hydrogels were synthesized by free radical solution polymerization with diverse weight ratios of polymer, monomer and cross linker. Total duration of study was 1.5 years from March 2013 to August 2015. The N, N-methylene bis acrylamide and potassium persulfate were used as crosslinker and initiator respectively. Hydrogels were characterized for swelling ratio, equilibrium swelling, gel content, porosity and in vitro drug release. The surface morphology of synthesized hydrogels was evaluated by using Scanning Electron Microscopy. Thermal properties of hydrogels were evaluated by Thermogravimetric Analysis and Differential Scanning Calorimetry whereas FTIR was done to examine chemical compatibility. Finally, in vivo evaluation of prepared hydrogels was carried out in rabbits using simple parallel study design to estimate various pharmacokinetic parameters.Results: HPMC-co-AA hydrogels had good pH sensitivity whereas; they demonstrated maximum and minimum swelling at pH 7.4 and 1.2 respectively. Swelling ratio, gel fraction and cumulative percent drug release were decreased with increasing crosslinker concentration while these parameters were increased with increasing AA and HPMC concentrations. A porous network was observed in the SEM images. All formulation ingredients of prepared hydrogels showed good compatibility as determined by FTIR. Results of in vivo study proved the pH sensitivity and sustained drug release of prepared hydrogels.Conclusion: The HPMC-graft-AA hydrogels showed good pH-sensitivity and sustained-release profile for model drug nicorandil.

The optimal discovery procedure for significance analysis of general gene expression studies.

MotivationAnalysis of biological data often involves the simultaneous testing of thousands of genes. This requires two key steps: the ranking of genes and the selection of important genes based on a significance threshold. One such testing procedure, called the optimal discovery procedure (ODP), leverages information across different tests to provide an optimal ranking of genes. This approach can lead to substantial improvements in statistical power compared to other methods. However, current applications of the ODP have only been established for simple study designs using microarray technology. Here, we extend this work to the analysis of complex study designs and RNA-sequencing studies.ResultsWe apply our extended framework to a static RNA-sequencing study, a longitudinal study, an independent sampling time-series study,and an independent sampling dose–response study. Our method shows improved performance compared to other testing procedures, finding more differentially expressed genes and increasing power for enrichment analysis. Thus, the extended ODP enables a favorable significance analysis of genome-wide gene expression studies.Availability and implementationThe algorithm is implemented in our freely available R package called edge and can be downloaded at https://www.bioconductor.org/packages/release/bioc/html/edge.html.Supplementary information Supplementary data are available at Bioinformatics online.

Twilight activity patterns and angling vulnerability of yellowmouth barracuda (Sphyraena viridensis Cuvier, 1829), a range-expanding thermophilic fish.

Among the thermophilic fishes that have become established in the north-western Mediterranean as a consequence of sea warming, the yellowmouth barracuda (Sphyraena viridensis Cuvier, 1829) appears to be one of the most successful and abundant in the coastal rocky environment, having increasingly become the object of recreational and commercial exploitation in the study area. Lure-fishing sessions were carried out from May 2016 to November 2018 in the Catalan Sea (NE Spain) at dawn and dusk, with the aim of providing new insight into the behavioural, spatial and feeding ecology and vulnerability to angling of this poorly known species. Generalized mixed-effects linear models showed that S. viridensis is a crepuscular inshore dweller, whose vulnerability to angling is significantly influenced by solar and lunar light intensities, being highest in the pre-spawn and spawning periods. Asymmetries between dawn and dusk activity patterns were detected, evidently related to a drop in aggressiveness at dusk following the spawning period. The simple study design adopted may be applied to other contexts, aiming to the recognition of several levels of fish vulnerability to angling.

Computing the Expected Value of Sample Information Efficiently: Practical Guidance and Recommendations for Four Model-Based Methods.

Value of information (VOI) analyses can help policy makers make informed decisions about whether to conduct and how to design future studies. Historically a computationally expensive method to compute the expected value of sample information (EVSI) restricted the use of VOI to simple decision models and study designs. Recently, 4 EVSI approximation methods have made such analyses more feasible and accessible. Members of the Collaborative Network for Value of Information (ConVOI) compared the inputs, the analyst's expertise and skills, and the software required for the 4 recently developed EVSI approximation methods. Our report provides practical guidance and recommendations to help inform the choice between the 4 efficient EVSI estimation methods. More specifically, this report provides: (1) a step-by-step guide to the methods' use, (2) the expertise and skills required to implement the methods, and (3) method recommendations based on the features of decision-analytic problems.

A Descriptive Study to assess the level of Knowledge regarding Consequences of Internet Addiction among Adolescents in SGRR Public School, Patel Nagar, Dehradun

A descriptive study was conducted to assess the level of knowledge regarding consequences of internet addiction among adolescents in SGRR Public School, Patel Nagar, Dehradun. A simple descriptive study design with cross sectional survey method was used for this study. The setting of the study was SGRR public school at Dehradun. Population for the present study was adolescents from the private public school. The samples for the present study were comprised of 60 adolescent school children selected by purposive sampling technique. The tool used for data collection is questionnaire. The percentage wise distribution shows that highest percentage (75%) of the samples were having average knowledge regarding consequences, (23%) of them were having good knowledge whereas only (2%) of them were having poor knowledge. It shows that the samples were having previous knowledge regarding the topic. The overall mean score of knowledge regarding consequences of internet addiction among samples was 21.45 and standard deviation was 4.918. There was no association between the level of knowledge regarding consequences of internet addiction with their selected demographic variables.

Simple study designs in ecology produce inaccurate estimates of biodiversity responses

Abstract Monitoring the impacts of anthropogenic threats and interventions to mitigate these threats is key to understanding how to best conserve biodiversity. Ecologists use many different study designs to monitor such impacts. Simpler designs lacking controls (e.g. Before–After (BA) and After) or pre‐impact data (e.g. Control–Impact (CI)) are considered to be less robust than more complex designs (e.g. Before–After Control‐Impact (BACI) or Randomized Controlled Trials (RCTs)). However, we lack quantitative estimates of how much less accurate simpler study designs are in ecology. Understanding this could help prioritize research and weight studies by their design's accuracy in meta‐analysis and evidence assessment. We compared how accurately five study designs estimated the true effect of a simulated environmental impact that caused a step‐change response in a population's density. We derived empirical estimates of several simulation parameters from 47 ecological datasets to ensure our simulations were realistic. We measured design performance by determining the percentage of simulations where: (a) the true effect fell within the 95% Confidence Intervals of effect size estimates, and (b) each design correctly estimated the true effect's direction and magnitude. We also considered how sample size affected their performance. We demonstrated that BACI designs performed: 1.3–1.8 times better than RCTs; 2.9–4.2 times versus BA; 3.2–4.6 times versus CI; and 7.1–10.1 times versus After designs (depending on sample size), when correctly estimating true effect's direction and magnitude to within ±30%. Although BACI designs suffered from low power at small sample sizes, they outperformed other designs for almost all performance measures. Increasing sample size improved BACI design accuracy, but only increased the precision of simpler designs around biased estimates. Synthesis and applications. We suggest that more investment in more robust designs is needed in ecology since inferences from simpler designs, even with large sample sizes may be misleading. Facilitating this requires longer‐term funding and stronger research–practice partnerships. We also propose ‘accuracy weights’ and demonstrate how they can weight studies in three recent meta‐analyses by accounting for study design and sample size. We hope these help decision‐makers and meta‐analysts better account for study design when assessing evidence.

Competencias para la lectura y escritura del idioma inglés presentes en los estudiantes de una universidad venezolana

El estudio tuvo como propósito Develar las competencias de lectura y escritura de los estudiantes del Programa de Educación en Lengua Extranjera Mención Inglés (ILE) de la UNEFM Municipalizada Carirubana, estado Falcón, Venezuela. Se enmarcó dentro del paradigma cualitativo, con un diseño de estudio de caso simple debido a que se trabajó con un solo escenario. Los informantes claves fueron seis (06) estudiantes del Programa de ILE de la UNEFM Municipalizada, del período I-2018. Para conocer a fondo el escenario de estudio y su problemática se utilizó la técnica de la entrevista en profundidad. El análisis de la información se realizó con el apoyo del software Atlas Ti 6.0, de donde se extrajeron los códigos y se estructuraron en redes semánticas, revelando que la carencia de un vocabulario amplio, deficiencias en la cohesión y coherencia, aunado a la desmotivación del estudiante limitan notablemente la construcción de conocimiento en esta área y el desarrollo de sus competencias lingüísticas.

Functional outcomes of mutualistic network interactions: A community‐scale study of frugivore gut passage on germination

Abstract Current understanding of mutualistic networks is grounded largely in data on interaction frequency, yet mutualistic network dynamics are also shaped by interaction quality—the functional outcomes of individual interactions on reproduction and survival. The difficulty of obtaining data on functional outcomes has resulted in limited understanding of functional variation among a network's pairwise species interactions, of the study designs that are necessary to capture major sources of functional variation, and of predictors of functional variation that may allow generalization across networks. In this community‐scale study, we targeted a key functional outcome in plant–frugivore networks: the impact of frugivore gut passage on seed germination. We used captive frugivore feeding trials and germination experiments in an island ecosystem, attaining species‐level coverage across all extant native frugivores and the plants they consume to (a) assess sources of functional variation, (b) separate effects of pulp removal from those of scarification via gut passage, and (c) test trait‐based correlates of gut passage effect sizes. We found antagonistic seed predation effects of a frugivore previously assumed to be a seed disperser, highlighting the need to consider functional outcomes rather than interaction frequency alone. The other frugivores each exhibited similar impacts for individual plant species, with benefits primarily caused by pulp removal rather than scarification, supporting the use of animal functional groups in this context. In contrast, plant species varied widely in impacts of gut passage on germination. Species with smaller seeds and more frugivore partners had larger benefits of gut passage, showing promise for network metrics and functional traits to predict functional variation among plants. Synthesis. Combining network and demographic approaches, we assessed the degree and sources of variation in a key functional outcome of plant–frugivore interactions across an entire network. Using a detailed study design, our work shows how simpler study designs can capture primary sources of functional variation and that functional traits and network metrics may allow generalization across networks. Efficiently measuring and generalizing sources of functional variation within mutualistic networks will strengthen our ability to model network dynamics and predict mutualist responses to global change.

A preliminary survey of major diseases of ruminants and management practices in Western Tigray province, northern Ethiopia

BackgroundDespite the highest population, the productivity of Ethiopian livestock is low, and the direct contribution to the national economy is limited. Poor genetic potential, shortage of feed in quantity and quality, poor health care and management practices are the main contributors to low productivity and production. Data on animal disease and management practices are not in place, in this regard; we estimate the burden of animal health ailments and management practices in ruminants via simple cross-sectional study design in randomly selected peasant associations in western Tigray of northern Ethiopia.ResultsA preliminary disease survey in ruminants and their management practices comprising of cattle, sheep and goats was undertaken to evaluate the existence, burden of ruminant diseases and management practices. A total of 121 randomly selected household respondents of Maikhadrah and Bakhar (26.2%), Dansha (19.7%), Adi-Hirdi (18.0%), Adi-Remets and Inda-Selassie (36.1%) sub-districts were inspected throughout the study period. Most (81%) of farmers feed their animals on free grazing in the open environment travelling from highlands and midlands to lowlands in search of adequate feed (different species of grasses) and crop residues during the wet season up to the beginning of the dry season. Majority of farmers (43.8%) had veterinary access from governmental veterinary officers. Thirty-four (33.9%) of the respondents got veterinary access from illegal drug dealers in mini shops or market. Among the major disease constraints identified; Tick infestation (89.3%), lice infestation (68.6%) mange mite infestation (77.7%) lumpy skin disease (LSD) (42.1%), trypanasomiasis (62.8%) bovine pasteurellosis (52.1) mastitis (13.2%), sheep and goat pox (15.7), abortion (19.0%), dystocia (24.8%), retained fetal membrane (25.6%), prolapsed uterus (13.2%) delayed heat period (38.8%) were most endemic ailments directly affecting livestock production and farmers livelihood.ConclusionIn conclusion management practices in livestock production is poor to a large extent. Burden and endemicity of livestock diseases are substantially higher. The data obtained could be the source of facts for planners in animal health service delivery system in this sub region.