Robustness Through Regime Flips in Collapsing Ecological Networks

© 2019, Crown. There has been considerable progress in our perception of organized complexity in recent years. Recurrent debates on the dynamics and stability of complex systems have provided several insights, but it is very difficult to find identifiable patterns in the relationship between complex network structure and dynamics. Traditionally an arena for theoreticians, much of this research has been invigorated by demonstration of alternate stable states in real world ecosystems such as lakes, coral reefs, forests and grasslands. In this work, we use topological connectivity attributes of eighty six ecological networks and link these with random and targeted perturbations, to obtain general patterns of behaviour of complex real world systems. We have analyzed the response of each ecological network to individual, grouped and cascading extinctions, and the results suggest that most networks are robust to loss of specialists until specific thresholds are reached in terms of network geodesics. If the extinctions persist beyond these thresholds, a state change or ‘flip’ occurs and the structural properties are altered drastically, although the network does not collapse. As opposed to simpler or smaller networks, we find larger networks to contain multiple states that may in turn, ensure long-term persistence, suggesting that complexity can endow resilience to ecosystems. The concept of critical transitions in ecological networks and the implications of these findings for complex systems characterized by networks are likely to be profound with immediate significance for ecosystem conservation, invasion biology and restoration ecology.Non

The Effect of Cyclic Heat Stress Applied to Different Broiler Chicken Brooding Stages on Animal Performance and Carcass Yield

ABSTRACT The objective of this study was to evaluate the performance and carcass yield of broilers submitted to heat stress during different rearing stages. A total of 840 one-day-old CobbAvian48TM male broilers were housed in an experimental house equipped with conventional ventilation system and foggers. Birds were distributed according to a completely randomized design into four treatments, with six replicates of 35 birds each. The treatments consisted of: T1 (control) - birds reared under natural temperature and relative humidity conditions from 1 to 42 days of age; T2 - birds submitted to heat stress (HS) from 16 to 21 days of age; T3 - birds submitted to HS from 22 to 42 days of age; and T4 - birds submitted to HS from 16 to 42 days of age. Birds were submitted to heat stress daily for one hour (12:00-13:00h).On day 42, performance data were determined. Six birds per replicate were selected and sacrificed to obtain carcass, parts, and giblet weights and yields. Performance parameters were not influenced by the treatments. Broilers submitted to 1-h cyclic heat between 16 and 42 days of age presented lower deboned breast weight compared with those maintained in natural temperature and relative humidity conditions. It was concluded that the performance of broilers submitted to short cyclic heat periods is not impaired

Óbito durante tratamento da leishmaniose tegumentar americana com stibogluconato de sódio bp 88® (shandong xinhua) Fatal case during treatment of american tegumentary leishmaniasis with sodium stibogluconate bp 88® (shandong xinhua)

Os autores relatam a ocorrência de óbito em paciente portador da forma cutânea da LTA no município de Caxias-MA. Trata-se de paciente do sexo masculino, 22 anos, gari, portador de lesão ulcerada no membro inferior (perna esquerda), diagnosticado, após encontro do parasita (Leishmania) na lesão, tratado com stibogluconato de sódio BP88® (Shandong Xinhua) na dose de 10mg/Sb+5/kg/dia/20 dias. Após a 3ª dose apresentou dores articulares, naúseas, mal estar geral. Com a continuação da medicação houve agravamento do quadro com dor epigástrica e no hipocôndrio direito irradiando-se para o hemitórax homolateral. Após a 7ª dose apresentou dispnéia associado à dor torácica de leve intensidade. Na 9ª dose houve piora do quadro, mesmo assim continuou a usar o medicamento até a 11ª dose quando seu estado agravou-se. Foi internado, necessitando de tratamento intensivo. Nos exames realizados apresentou: 4,4 milhões de eritócitos, 10,6% de hemoglobina, 35% de hematócrito, 26.400 de leucócitos, basófilos e mielócitos (0), 59% de segmentados, 30% de linfócitos, 2% de monócitos, plaquetas (normais), glicose 42mg%, uréia 73mg%, creatinina (2,4mg%), eletrocardiograma (bloqueio de ramo direito). Veio a falecer tendo como causa do óbito, insuficiência cárdio respiratória. O relato atual mostra a necessidade de esclarecimento das equipes de saúde quanto ao uso dos Sb+5 e também lembrar o Ministério da Saúde quando da aquisição de novos produtos, preocupar-se com a qualidade e procedência do mesmo.<br>The authors report the occurrence of a fatal case in patient with cutaneous leishmaniasis in the municipality of Caxias, MA. Male patient, 22 years old, road sweeper, presented with an ulcer in left leg, diagnosed as cutaneous leishmaniasis and treated with sodium stibogluconate BP88®(Sb+5) (Shandong Xinhua) at a dose of 10mg/Sb+5/kg/day/20 days. After dose three he presented arthralgia, myalgia, nausea and weakness. During the therapy there was an aggravation of the symptoms with abdominal pain and irradiation into the thorax. After dose seven he presented a picture of associated dyspnea and thoracic pain of mild intensity. At dose nine there was further worsening of the picture, nevertheless the therapy was continued up to dose 11, when the patient's state deteriorated to such an extent that he was hospitalized in the intensive care unit. Exams: erythrocytes, 4.4 million; hemoglobin, 10.6%; hematocrits, 35%; white blood cells 26,400, basophiles and myelocytes (0); segmented leukocytes, 59%; lymphocytes 30%; monocytes 2%; platelets (normal); glucose, 42mg%; urea, 73mg%; creatinine, 2.4mg%; and ECG (blockade of right branch). The patient died from cardiorespiratory insufficiency. The current report underscores the need to clarify health workers regarding the use of Sb+5 and also to remind the Health Ministry to verify the quality and origin when acquiring new products

Gait analysis comparing Parkinson's disease with healthy elderly subjects Comparação da doença de Parkinson com idosos saudáveis através da análise da marcha

There is a lack of studies comparing the kinematics data of idiopathic Parkinson's disease (IPD) patients with healthy elder (HE) subjects, and when there is such research, it is not correlated to clinical measures. OBJECTIVE: To compare the spatio-temporal and kinematic parameters of Parkinsonian gait with the HE subjects group and measure the relation between these parameters and clinical instruments. METHOD: Twelve patients with IPD and fifteen HE subjects were recruited and evaluated for clinical instruments and gait analysis. RESULTS: There were statistically significant differences between HE group and the IPD group, in stride velocity, in stride length (SL), and in the hip joint kinematic data: on initial contact, on maximum extension during terminal contact and on maximum flexion during mid-swing. Regarding the clinical instruments there were significant correlated with in stride velocity and SL. CONCLUSION: Clinical instruments used did not present proper psychometric parameters to measure the IPD patient's gait, while the 3D system characterized it better.<br>Poucos estudos comparam os dados cinemáticos de pacientes com doença de Parkinson idiopática (DPI) com indivíduos idosos saudáveis, e quando realizam não correlacionam com medidas clínicas. OBJETIVO: Comparar os parâmetros espaço-temporais e cinemáticos da marcha na DP com os de idosos saudáveis (IS) e avaliar a relação entre estes parâmetros com os instrumentos clínicos. MÉTODO: Doze pacientes com DPI e quinze IS foram recrutados e avaliados por instrumentos clínicos e de análise de marcha. RESULTADOS: Houve diferenças estatísticas significantes entre o grupo de IS e o de DPI na velocidade da marcha e no comprimento do passo (CP), nos dados cinemáticos das articulações do quadril: no contato inicial, na máxima extensão no apoio e na máxima flexão na oscilação. No que diz respeito aos instrumentos clínicos houve significativa correlação com a velocidade da marcha e SL. CONCLUSÃO: Os instrumentos clínicos utilizados não apresentaram adequados parâmetros psicométricos para a avaliação da marcha dos indivíduos com DPI, enquanto uma avaliação em 3D caracteriza melhor a marcha destes indivíduos