Dynamic Analysis of a Population Competition Model with Disease in One Species and Group Defense in Another Species

2020 ◽  
Vol 30 (12) ◽  
pp. 2050181
Author(s):  
Xue Cheng ◽  
Jianfeng Luo ◽  
Yi Zhao
Keyword(s):  
Predator Population ◽  
Isolated Population ◽  
Defensive Strategy ◽  
First Case ◽  
Existence And Stability ◽  
Group Defense ◽  
Population Competition ◽  
Competition Parameter ◽  
Transmissible Disease

In this paper, we study the dynamics of an ecoepidemic competition system where the individuals of one population gather together in herds with a defensive strategy, showing social behavior, while another predator population is subject to a transmissible disease and behaves individually. By analyzing the existence and stability of the equilibria of the system, we find that the relatively isolated population can be eradicated, or the population with group defense can live alone eventually under some constraints. Infected individuals end up in two possible situations. In the first case, the disease is eventually eliminated, meaning that only healthy and group-defense individuals in the system can survive. In the other case, the spread of the disease is controlled and eventually all three individuals can coexist. We also conduct a correlation analysis using competition parameter and recovery rate of disease as birfurcation parameters in order to study the transcritical bifurcation, saddle-node bifurcation and Hopf bifurcation. The long-term dynamics of the boundary and interior equilibria are demonstrated by numerical simulations.

Population fragmentation causes inadequate gene flow and increases extinction risk

2017 ◽  
Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  
Keyword(s):  
Gene Flow ◽  
Extinction Risk ◽  
Random Mating ◽  
Large Population ◽  
Isolated Population ◽  
Population Fragmentation ◽  
Single Population ◽  
Total Size ◽  
Limited Gene Flow

Most species now have fragmented distributions, often with adverse genetic consequences. The genetic impacts of population fragmentation depend critically upon gene flow among fragments and their effective sizes. Fragmentation with cessation of gene flow is highly harmful in the long term, leading to greater inbreeding, increased loss of genetic diversity, decreased likelihood of evolutionary adaptation and elevated extinction risk, when compared to a single population of the same total size. The consequences of fragmentation with limited gene flow typically lie between those for a large population with random mating and isolated population fragments with no gene flow.

scholarly journals COVID-19 Response in Thailand and Its Implications on Future Preparedness

2021 ◽  
Vol 18 (3) ◽  
pp. 1089
Author(s):  
Wijitbusaba Marome ◽  
Rajib Shaw
Keyword(s):  
Early Stage ◽  
Health Resources ◽  
Holistic Approach ◽  
Disaster Risk ◽  
Community Level ◽  
Multilateral Cooperation ◽  
First Case ◽  
Multiple Dimensions ◽  
Economic And Social Impacts

Thailand has been affected by COVID-19, like other countries in the Asian region at an early stage, and the first case was reported as early as mid-January 2020. Thailand’s response to the COVID-19 pandemic has been guided by the “Integrated Plan for Multilateral Cooperation for Safety and Mitigation of COVID-19”. This paper analyses the health resources in the country and focuses on the response through community-level public health system and legislative measures. The paper draws some lessons on future preparedness, especially with respect to the four priorities of Sendai Framework for Disaster Risk Reduction. At the end, the paper puts some key learning for future preparedness. While Thailand’s response to COVID-19 has been effective in limiting the spread of the disease, it falls short at being able to address the multiple dimensions of the crisis such as the economic and social impacts. The socioeconomic sectors have been hardest hit, with significant impact on tourism sectors. Sociopolitical system also plays an important role in governance and decision-making for pandemic responses. The analysis suggests that one opportunity for enhancing resilience in Thailand is to strive for more multilevel governance that engages with various stakeholders and to support grassroots and community-level networks. The COVID-19 pandemic recovery is a chance to recover better while leaving no one behind. An inclusive long-term recovery plan for the various impacted countries needs to take a holistic approach to address existing gaps and work towards a sustainable society. Furthering the Health Emergency Disaster Risk Management (HEDRM) Framework may support a coordinated response across various linked sectors rather than straining one particular sector.

scholarly journals Hypocalcemic cardiomyopathy after parathyroidectomy in a patient with uremia: A case report and literature review

2020 ◽  
Vol 48 (7) ◽  
pp. 030006052094211
Author(s):  
Wei Zhang ◽  
Feng Xue ◽  
Quandong Bu ◽  
Xuemei Liu
Keyword(s):  
Heart Failure ◽  
Case Report ◽  
Secondary Hyperparathyroidism ◽  
Calcium Supplementation ◽  
Severe Heart Failure ◽  
Cardiac Complications ◽  
Refractory Heart Failure ◽  
First Case ◽  
Insight Into

Hypocalcemia is a rare, but reversible, cause of dilated cardiomyopathy. Although cardiomyopathy may cause severe heart failure, calcium supplementation can reverse heart failure. We report here a patient with uremia and secondary hyperparathyroidism, who was complicated by persistent hypocalcemia and refractory heart failure. The cardiac failure was refractory to treatment with digitalis and diuretics, but dramatically responded to calcium therapy and restoration of normocalcemia. As a result, the patient was eventually diagnosed with hypocalcemic cardiomyopathy. To the best of our knowledge, this is the first case of this disease to be reported in a patient with uremia. Findings from our case may help clinicians to better understand hypocalcemic cardiomyopathy. Our case might also provide new insight into long-term cardiac complications and prognoses of patients undergoing parathyroidectomy due to secondary hyperparathyroidism.

The effect of research activities and winter precipitation on voiding behaviour of Agassiz’s desert tortoises (Gopherus agassizii)

2014 ◽  
Vol 41 (8) ◽  
pp. 641 ◽  
Author(s):  
Mickey Agha ◽  
Mason O. Murphy ◽  
Jeffrey E. Lovich ◽  
Joshua R. Ennen ◽  
Christian R. Oldham ◽  
...  
Keyword(s):  
Stress Responses ◽  
Handling Time ◽  
Winter Precipitation ◽  
Contact Period ◽  
Gopherus Agassizii ◽  
Desert Tortoise ◽  
Defensive Strategy ◽  
Survivorship Analysis ◽  
Research Activities

Context There is little information available on how research activities might cause stress responses in wildlife, especially responses of threatened species such as the desert tortoise (Gopherus agassizii). Aims The present study aims to detect behavioural effects of researcher handling and winter precipitation on a natural population of desert tortoises in the desert of Southwestern United States, over the period 1997 to 2014, through extensive assessments of capture events during multiple research studies, and capture–mark–recapture survivorship analysis. Methods Juvenile and adult desert tortoises were repeatedly handled with consistent methodology across 18 years during 10 study seasons. Using a generalised linear mixed-effects model, we assessed the effects of both research manipulation and abiotic conditions on probability of voiding. Additionally, we used a Cormack–Jolly–Seber model to assess the effects of winter precipitation and voiding on long-term apparent survivorship. Key results Of 1008 total capture events, voiding was recorded on 83 (8.2%) occasions in 42 different individuals. Our top models indicated that increases in handling time led to significantly higher probabilities of voiding for juveniles, females and males. Similarly, increases in precipitation resulted in significantly higher probabilities of voiding for juveniles and females, but not for males. Tortoise capture frequency was negatively correlated with voiding occurrence. Cormack–Jolly–Seber models demonstrated a weak effect of winter precipitation on survivorship, but a negligible effect for both voiding behaviour and sex. Conclusions Handling-induced voiding by desert tortoises may occur during common research activities and years of above average winter precipitation. Increased likelihood of voiding in individuals with relatively low numbers of recaptures suggested that tortoises may have perceived researchers initially as predators, and therefore voided as a defensive strategy. Voiding does not appear to impact long-term survivorship in desert tortoises at this site. Implications This study has demonstrated that common handling practices on desert tortoise may cause voiding behaviour. These results suggest that in order to minimise undesirable behavioural responses in studied desert tortoise populations, defined procedures or protocols must be followed by the investigators to reduce contact period to the extent feasible.

scholarly journals Secondary Adrenal Insufficiency after Treatment with Budesonide for Autoimmune Hepatitis

2018 ◽  
Vol 12 (3) ◽  
pp. 597-601 ◽  
Author(s):  
Filip De Maeyer ◽  
Bruno Lapauw ◽  
Anne Hoorens ◽  
Anja Geerts ◽  
Hans Van Vlierberghe ◽  
...  
Keyword(s):  
Autoimmune Hepatitis ◽  
Adrenal Insufficiency ◽  
Attractive Alternative ◽  
Secondary Adrenal Insufficiency ◽  
Systemic Activity ◽  
Immunosuppressive Medication ◽  
Systemic Corticosteroids ◽  
First Case ◽  
First Pass

Autoimmune hepatitis (AIH) is a rare cause of chronic liver disease. The backbone of treatment is immunosuppressive medication, typically prednisolone as induction therapy and azathioprine as a maintenance therapy. Side effects of the long-term use of systemic corticosteroids are well known and have led to the use of alternative induction regimens. An attractive alternative is budesonide, a nonhalogenated glucocorticosteroid characterized by a high first-pass effect in the liver (90%), resulting in a high topical anti-inflammatory activity and a low systemic activity. It should be stressed that budesonide is contraindicated in patients with established cirrhosis with portal hypertension and portocaval shunting. In this case report, we present the first case of adrenal insufficiency following treatment with budesonide for AIH.

scholarly journals Management of Missed Traumatic Achilles Tendon Rupture in a Pediatric Patient: A Case Report

2021 ◽  
Vol 9 (4) ◽  
pp. 465-470
Author(s):  
Saad Andaloussi
Keyword(s):  
Achilles Tendon ◽  
Tendon Rupture ◽  
Achilles Tendon Rupture ◽  
Tendon Repair ◽  
Skin Wound ◽  
Plantaris Tendon ◽  
First Case ◽  
Tendon Ruptures ◽  
Post Traumatic

BACKGROUND: Missed traumatic Achilles tendon ruptures in children are rarely reported in the literature. Various techniques have been described to reconstruct delayed Achilles tendon ruptures for adults, but the long-term consequences in the growing child are unknown. CLINICAL CASE: The article presents a clinical observation of a 8-year-old girl with missed rupture of the Achilles tendon operated 7 weeks after the trauma by end-to-end Kessler-type sutures augmented with the plantaris tendon. At 2-year follow-up, the patient was completely asymptomatic. DISCUSSION: A review of the literature shows that this is the third neglected pediatric case of post-traumatic Achilles tendon rupture. The first case concerns a 10-year-old boy treated successfully six weeks after the traumat by open surgical repair using the Bunnell sutures technique. The second patient was a 7-year-old girl, she was operated 8 weeks after the trauma with a termino-terminal tenorrhaphy using the Bunnell technique augmented with the plantaris tendon. CONCLUSIONS: Using the plantaris tendon to reinforce the Achilles tendon repair offers satisfactory results with minimal morbidity. Prognosis depends on the extent of tendon defect which determines the long-term functional outcome. Any skin wound that sits on the back of the leg requires a systematic and careful physical examination to check the integrity of the Achilles tendon.

scholarly journals Alternative Leprosy Treatment Using Rifampicin Ofloxacin Minocycline (ROM) Regimen – Two Case Reports

2019 ◽  
Vol 11 (3) ◽  
pp. 89-93
Author(s):  
Yohanes Widjaja ◽  
Khairuddin Djawad ◽  
Saffruddin Amin ◽  
Widyawati Djamaluddin ◽  
Dirmawati Kadir ◽  
...  
Keyword(s):  
Clinical Improvement ◽  
Alternative Treatment ◽  
Histopathological Examination ◽  
Case Reports ◽  
Erythematous Plaque ◽  
First Case ◽  
Satisfactory Outcome ◽  
Significant Clinical Improvement ◽  
The Right

Abstract Introduction. Leprosy is a disease that predominantly affects the skin and peripheral nerves, resulting in neuropathy and associated long-term consequences, including deformities and disabilities. According to the WHO classification, there are two categories of leprosy, paucibacillary (PB) and multibacillary (MB). The standard treatment for leprosy employs the use of WHO MDT (Multi Drug Treatment) regimen, despite its multiple downsides such as clofazimine-induced pigmentation, dapsone-induced haematological adverse effects, poor compliance due to long therapy duration, drug resistance, and relapse. Multiple studies and case reports using ROM regimen have reported satisfactory results. Nevertheless, there are still insufficient data to elucidate the optimum dosage and duration of ROM regimen as an alternative treatment for leprosy. Previous experience from our institution revealed that ROM regimen given three times weekly resulted in a satisfactory outcome. Case Reports. We report two cases of leprosy treated with ROM regimen from our institution. The first case was PB leprosy in a 64-year-old male who presented with a single scaly plaque with erythematous edge on the right popliteal fossa. Sensibility examination showed hypoesthesia with no peripheral nerve enlargement. Histopathological examination confirmed Borderline Tuberculoid leprosy. ROM regimen was started three times weekly for 6 weeks and the patient showed significant clinical improvement at the end of the treatment with no reaction or relapse until after 6 months after treatment. The second case was MB leprosy in a 24-year-old male patient with clawed hand on the 3rd-5th phalanges of the right hand and a hypoesthetic erythematous plaque on the forehead. Histopathology examination confirmed Borderline leprosy. The patients received ROM therapy 3 times a week with significant clinical improvement after 12 weeks. Conclusion. ROM regimen given three times weekly for 6 weeks in PB leprosy and 12 weeks in MB leprosy resulted in a significant clinical improvement. Thus, ROM regimen could be a more effective, safer, faster alternative treatment for leprosy.

scholarly journals Reassortment and persistence of influenza A viruses from diverse geographic origins within Australian wild birds: evidence from a small, isolated population of Ruddy turnstones

2021 ◽  
Author(s):  
Bethany J. Hoye ◽  
Celeste M. Donato ◽  
Simeon Lisovski ◽  
Yi-Mo Deng ◽  
Simone Warner ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Low Density ◽  
Isolated Population ◽  
Influenza A Viruses ◽  
Geographic Origins ◽  
Eastern Australia

Australian lineages of avian influenza A viruses (AIVs) are thought to be phylogenetically distinct from those circulating in Eurasia and the Americas, suggesting the circulation of endemic viruses seeded by occasional introductions from other regions. However, processes underlying the introduction, evolution and maintenance of AIVs in Australia remain poorly understood. Waders (Order Charadriiformes, Family Scolopacidae) may play a unique role in the ecology and evolution of AIVs, particularly in Australia, where ducks, geese and swans (Order Anseriformes, Family Anatidae) rarely undertake intercontinental migrations. Across a five-year surveillance period (2011–2015), Ruddy turnstones (Arenaria interpres) that ‘overwinter’ during the Austral summer in south eastern Australia showed generally low levels of AIV prevalence (0–2%). However, in March 2014 we detected AIVs in 32% (95% CI; 25–39%) of individuals in a small, low-density, island population 90km from the Australian mainland. This epizootic comprised three distinct AIV genotypes, each of which represent a unique reassortment of Australian, recently introduced Eurasian, and recently introduced American-lineage gene segments. Strikingly, the Australian-lineage gene segments showed high similarity to H10N7 viruses isolated in 2010 and 2012 from poultry outbreaks 900–1500km to the north. Together with the diverse geographic origins of the American and Eurasian gene segments, these findings suggest extensive circulation and reassortment of AIVs within Australian wild birds over vast geographic distances. Our findings indicate that long-term surveillance in waders may yield unique insights into AIV gene flow, especially in geographic regions like Oceania where Anatidae do not display regular inter- or intracontinental migration. IMPORTANCE High prevalence of avian influenza viruses (AIVs) was detected in a small, low-density, isolated population of Ruddy turnstones in Australia. Analysis of these viruses revealed relatively recent introductions of viral gene segments from both Eurasia and North America, as well as long-term persistence of introduced gene segments in Australian wild birds. These data demonstrate that the flow of viruses into Australia may be more common than initially thought and that, once introduced, these AIVs have the potential to be maintained within the continent. These findings add to a growing body of evidence suggesting Australian wild birds are unlikely to be ecologically-isolated from the highly pathogenic H5Nx viruses circulating among wild birds throughout the northern hemisphere.

Galeazzi-equivalent Fractures: Report of Two Cases and Literature Review

2017 ◽  
Vol 22 (02) ◽  
pp. 232-235
Author(s):  
Seigo Suganuma ◽  
Kaoru Tada ◽  
Daiki Yamamoto ◽  
Hiroyuki Tsuchiya
Keyword(s):  
Emergency Surgery ◽  
Case Reports ◽  
Growth Arrest ◽  
Short Term ◽  
Rare Injury ◽  
First Case ◽  
Long Term Follow Up ◽  
Epiphyseal Injury

The Galeazzi-equivalent fracture is a rare injury that occurs in children. The most important issue is the distal ulnar epiphyseal injury. Although there have been some case reports, most of them performed only short term follow-up. This article describes two cases of this fracture with long term follow-up until epiphyseal closure. First case is a 12-year-old girl who sustained a Galeazziequivalent fracture of her right forearm and underwent emergency surgery. At follow-up of 5 years and 10 months postsurgery, radiographs show ulnar growth arrest of one mm and she has mild pain. Second case is a 15-year-old boy who sustained an open Galeazzi-equivalent fracture of his left forearm and underwent emergency surgery. At follow-up of 3 years and 3 months postsurgery, radiographs show no growth arrest of the distal ulna. He has no residual complaint. Long term follow-up is absolutely necessary to monitor ulnar growth.

scholarly journals Drug-Induced Autoimmune Hepatitis following Treatment with Zoledronic Acid

2017 ◽  
Vol 11 (2) ◽  
pp. 440-445 ◽  
Author(s):  
Jenny Sarah Schneider ◽  
Matteo Montani ◽  
Felix Stickel
Keyword(s):  
Liver Disease ◽  
Zoledronic Acid ◽  
Side Effects ◽  
Liver Injury ◽  
Drug Reactions ◽  
Drug Induced ◽  
Drug Induced Liver Injury ◽  
First Case ◽  
Alternative Drugs

Adverse drug reactions are among the most frequent side effects of synthetic and complementary alternative drugs and represent the premier causes of license revocations and acute liver failure. Drug-induced liver injury can resemble literally any other genuine liver disease and usually responds well to drug dechallenge. However, in some cases autoimmune-like hepatitis can evolve, requiring short- and sometimes long-term immunosuppression. Here, we present the hitherto first case of autoimmune-like hepatitis following treatment with zoledronic acid.

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