The effect of accounting for biarticularity in hip flexor and hip extensor joint torque representations

Subject-specific torque-driven models have ignored biarticular effects at the hip. The aim of this study was to establish the contribution of monoarticular hip flexors and hip extensors to total hip flexor and total hip extensor joint torques for an individual and to investigate whether torque-driven simulation models should consider incorporating biarticular effects at the hip joint. Maximum voluntary isometric and isovelocity hip flexion and hip extension joint torques were measured for a single participant together with surface electromyography. Single-joint and two-joint representations were fitted to the collected torque data and used to determine the maximum voluntary joint torque capacity. When comparing two-joint and single-joint representations, the single-joint representation had the capacity to produce larger maximum voluntary hip flexion torque (larger by around 9% of maximum torque) and smaller maximum voluntary hip extension torque (smaller by around 33% of maximum torque) with the knee extended. Considering the range of kinematics found for jumping movements, the single-joint hip flexors had the capacity to produce around 10% additional torque, while the single joint hip extensors had about 70% of the capacity of the two-joint representation. Two-joint representations may overcome an over-simplification of single-joint representations by accounting for biarticular effects, while building on the strength of determining subject-specific parameters from measurements on the participant

Are joint torque models limited by an assumption of monoarticularity?

This study determines whether maximal voluntary ankle plantar flexor torque could be more accurately represented using a torque generator that is a function of both knee and ankle kinematics. Isovelocity and isometric ankle plantar flexor torques were measured on a single participant for knee joint angles of 111° to 169° (approximately full extension) using a Contrex MJ dynamometer. Maximal voluntary torque was represented by a 19-parameter two-joint function of ankle and knee joint angles and angular velocities with the parameters determined by minimizing a weighted root mean square difference between measured torques and the two-joint function. The weighted root mean square difference between the two-joint function and the measured torques was 10 N-m or 3% of maximum torque. The two-joint function was a more accurate representation of maximal voluntary ankle plantar flexor torques than an existing single-joint function where differences of 19% of maximum torque were found. It is concluded that when the knee is flexed by more than 40°, a two-joint representation is necessary

Adolescent depressive symptoms in India, Australia and USA: Exploratory Structural Equation Modelling of cross-national invariance and predictions by gender and age

Background The present study compares depressive symptoms in adolescents from three countries: Mumbai, India; Seattle, United States; and Melbourne, Australia measured using the Short Moods and Feelings Questionnaire (SMFQ). The study cross nationally compares SMFQ depressive symptom responses by age and gender. Methods Data from a cross-nationally matched survey were used to compare factorial and measurement characteristics from samples of students from Grade 7 and 9 in Mumbai, India (n=3268) with the equivalent cohorts in the Washington State, USA (n=1907) and Victoria, Australia (n=1900). Exploratory Structural Equation Modelling (ESEM) was used to cross-nationally examine factor structure and measurement invariance. Results A number of reports suggesting that SMFQ is uni-dimensional were not supported in findings from any country. A model with two factors was a better fit and suggested a first factor clustering symptoms that were affective and physiologically based symptoms and a second factor of self-critical, cognitive symptoms. The two-factor model showed convincing cross national configural invariance and acceptable measurement invariance. The present findings revealed that adolescents in Mumbai, India, reported substantially higher depressive symptoms in both factors, but particularly for the self-critical dimension, as compared to their peers in Australia and the USA and that males in Mumbai report high levels of depressive symptoms than females in Mumbai. Limitations the cross sectional study collected data for adolescents in Melbourne and Seattle in 2002 and the data for adolescents in Mumbai was obtained in 2010–2011 Conclusions These findings suggest that previous findings in developed nations of higher depressive symptoms amongst females compared to males may have an important cultural component and cannot be generalised as a universal feature of adolescent development

An isovelocity dynamometer method to determine monoarticular and biarticular muscle parameters

This study aimed to determine whether subject-specific individual muscle models for the ankle plantarflexors could be obtained from single joint isometric and isovelocity maximum torque measurements in combination with a model of plantarflexion. Maximum plantarflexion torque measurements were taken on one subject at six knee angles spanning full flexion to full extension. A planar three segment (foot, shank and thigh), two muscle (soleus and gastrocnemius) model of plantarflexion was developed. Seven parameters per muscle were determined by minimizing a weighted root mean square difference (wRMSD) between the model output and the experimental torque data. Valid individual muscle models were obtained using experimental data from only two knee angles giving a wRMSD score of 16 Nm, with values ranging from 11–17 Nm for each of the six knee angles. The robustness of the methodology was confirmed through repeating the optimization with perturbed experimental torques (±20%) and segment lengths (±10%) resulting in wRMSD scores of between 13–20 Nm. Hence, good representations of maximum torque can be achieved from subject-specific individual muscle models determined from single joint maximum torque measurements. The proposed methodology could be applied to muscle-driven models of human movement with the potential to improve their validity

Volatile metabolites associated with one aflatoxigenic and one nontoxigenic Aspergillus flavus strain grown on two different substrates

Aflatoxigenic and non-toxigenic Aspergillus flavus strains were grown on corn and on peanut substrates. Microbial volatile organic compounds (MVOCS) were collected by trapping headspace volatiles using thermal desorption tubes (TDT) packed with Tenax® TA and Carbotrap™ B. Samples were collected at various fungal growth stages. Trapped compounds were thermally desorbed from the adsorbent tubes, separated by gas chromatography, and identified by mass spectrometry. The fungal stage did not have many differences in the MVOCs but the concentrations of some volatiles changed over time depending on the substrate. Volatiles that were associated with both the aflatoxigenic A. flavus strain and the nontoxigenic strain on both substrates included: ethanol, 1-propanol, butanal, 2-methyl-1-propanol, 3-methylfuran, ethyl acetate, 1-butanol, 3-methylbutanal, 3-methyl-1-butanol, propanoic acid-2-methyl-ethyl-ester, 2-methyl-1-butanol, 1-pentanol, 2-pentanol, 3-methyl-3-buten-1-ol, benzaldehyde, 3-octanone, 2-ethyl-1-hexanol and octane. Volatiles that were associated only with the aflatoxigenic A. flavus strain included: dimethyl disulfide and nonanal. Volatiles that were associated only with the nontoxigenic A. fl avus strain included: hexanal, 1-hexanol, 1-octene-3-ol, 1-octen-3-one and 2-pentyl furan

Technology used to recognize activities of daily living in community-dwelling older adults

The use of technology has been suggested as a means of allowing continued autonomous living for older adults, while reducing the burden on caregivers and aiding decision-making relating to healthcare. However, more clarity is needed relating to the Activities of Daily Living (ADL) recognised, and the types of technology included within current monitoring approaches. This review aims to identify these differences and highlight the current gaps in these systems. A scoping review was conducted in accordance with PRISMA-ScR, drawing on PubMed, Scopus, and Google Scholar. Articles and commercially available systems were selected if they focused on ADL recognition of older adults within their home environment. Thirty-nine ADL recognition systems were identified, nine of which were commercially available. One system incorporated environmental and wearable technology, two used only wearable technology, and 34 used only environmental technologies. Overall, 14 ADL were identified but there was variation in the specific ADL recognised by each system. Although the use of technology to monitor ADL of older adults is becoming more prevalent, there is a large variation in the ADL recognised, how ADL are defined, and the types of technology used within monitoring systems. Key stakeholders, such as older adults and healthcare workers, should be consulted in future work to ensure that future developments are functional and useable

Allometric equation for Raphia laurentii De Wild, the commonest palm in the central Congo peatlands

The world’s largest tropical peatland lies in the central Congo Basin. Raphia laurentii De Wild, the most abundant palm in these peatlands, forms dominant to mono-dominant stands across approximately 45% of the peatland area. R. laurentii is a trunkless palm with fronds up to 20 m long. Owing to its morphology, there is currently no allometric equation which can be applied to R. laurentii. Therefore it is currently excluded from aboveground biomass (AGB) estimates for the Congo Basin peatlands. Here we develop allometric equations for R. laurentii, by destructively sampling 90 individuals in a peat swamp forest, in the Republic of the Congo. Prior to destructive sampling, stem base diameter, petiole mean diameter, the sum of petiole diameters, total palm height, and number of palm fronds were measured. After destructive sampling, each individual was separated into stem, sheath, petiole, rachis, and leaflet categories, then dried and weighed. We found that palm fronds represented at least 77% of the total AGB in R. laurentii and that the sum of petiole diameters was the best single predictor variable of AGB. The best overall allometric equation, however, combined the sum of petiole diameters (SDp), total palm height (H), and tissue density (TD): AGB = Exp(−2.691 + 1.425 × ln(SDp) + 0.695 × ln(H) + 0.395 × ln(TD)). We applied one of our allometric equations to data from two nearby 1-hectare forest plots, one dominated by R. laurentii, where R. laurentii accounted for 41% of the total forest AGB (with hardwood tree AGB estimated using the Chave et al. 2014 allometric equation), and one dominated by hardwood species, where R. laurentii accounted for 8% of total AGB. Across the entire region we estimate that R. laurentii stores around 2 million tonnes of carbon aboveground. The inclusion of R. laurentii in AGB estimates, will drastically improve overall AGB, and therefore carbon stock estimates for the Congo Basin peatlands

Functional diversity of chemokines and chemokine receptors in response to viral infection of the central nervous system.

Encounters with neurotropic viruses result in varied outcomes ranging from encephalitis, paralytic poliomyelitis or other serious consequences to relatively benign infection. One of the principal factors that control the outcome of infection is the localized tissue response and subsequent immune response directed against the invading toxic agent. It is the role of the immune system to contain and control the spread of virus infection in the central nervous system (CNS), and paradoxically, this response may also be pathologic. Chemokines are potent proinflammatory molecules whose expression within virally infected tissues is often associated with protection and/or pathology which correlates with migration and accumulation of immune cells. Indeed, studies with a neurotropic murine coronavirus, mouse hepatitis virus (MHV), have provided important insight into the functional roles of chemokines and chemokine receptors in participating in various aspects of host defense as well as disease development within the CNS. This chapter will highlight recent discoveries that have provided insight into the diverse biologic roles of chemokines and their receptors in coordinating immune responses following viral infection of the CNS

Incydenty sercowo-naczyniowe u pacjentów stosujących sildenafil - wyniki badania International Men’s Health Study

Wstęp: Celem pracy było oszacowanie częstości występowania poważnych incydentów sercowo-naczyniowych (np. zawał serca, udar) oraz całkowitej śmiertelności wśród mężczyzn z zaburzeniami erekcji otrzymujących sildenafil. Metody: Prospektywnym, obserwacyjnym badaniem kohortowym International Men’s Health Study (IMHS) objęto pacjentów ze zdiagnozowanymi zaburzeniami erekcji oraz wcześniej stosujących sildenafil lub dopiero zaczynających przyjmować ten preparat. Dane wyjściowe oraz z obserwacji odległej dotyczące chorób sercowo-naczyniowych (CVD), czynników ryzyka oraz zaburzeń erekcji uzyskano za pomocą odpowiednich kwestionariuszy. Do osób, które przebyły epizod sercowo-naczyniowy, wysłano kwestionariusze w celu zebrania informacji związanych z ekspozycją na sildenafil/leczeniem zaburzeń erekcji przed incydentem. Wyniki: W analizowanej grupie (n = 3813) odnotowano 35 incydentów sercowo-naczyniowych u 30 chorych. Częstość zgonu z jakiejkolwiek przyczyny, zawału serca oraz udaru wynosiła odpowiednio 0,4; 0,6 i 0,1 na każdych 100 pacjentolat obserwacji. W grupie 6 mężczyzn, którzy zgłosili stosowanie sildenafilu na miesiąc przed incydentem sercowo-naczyniowym, 2 podało jego użycie w czasie 24 godzin poprzedzających zdarzenie. Wnioski: Wyniki badania IMHS potwierdzają wcześniejsze doniesienia o współwystępowaniu zaburzeń erekcji oraz CVD i o podobnych czynnikach ryzyka tych chorób

Macrophage delivered HSV1716 is active against triple negative breast cancer

Oncolytic viruses (OV) promote anti-tumour responses through the initiation of immunogenic cancer cell death which activates the host’s systemic anti-tumour immunity. We have previously shown that intravenously administered HSV1716 is an effective treatment for mammary cancer. However, intravenous administration of a virus has the potential to result in neutralization and sequestration of the virus which may reduce efficacy. Here, we show that the oncolytic virus HSV1716 can be administered within a cellular carrier (macrophages). PyMT and 4T1 murine mammary cancer cell lines were implanted into immuno-competent murine models (orthotopic primary, early metastatic and brain metastasis models). HSV1716 or macrophages armed with HSV1716 (M-HSV1716) were administered intravenously, and tumour size was quantified using caliper measurement or bioluminescence imaging. Administration of M-HSV1716 led to tumour shrinkage and increased the survival of animals. Furthermore, these results were achieved with a 100-fold lower viral load, which has the potential for decreased toxicity. Our results demonstrate that M-HSV1716 is associated with activity against murine mammary cancers and provides an alternative platform for the systemic delivery of OV