bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is muscle involved in the mechanical adaptability of echinoderm mutable collagenous tissue?
Authors: Wilkie I. C. 
Published: April 2021

SUMMARYThe mutable collagenous tissue (MCT) of echinoderms has the capacity to change its mechanical properties in a time scale of less than 1 s to a few minutes under the influence of the nervous system. Although accumulating evidence indicates that the mechanical adaptability of MCT is due primarily to the modulation of interactions between components of the extracellular matrix, the presence of muscle in a few mutable collagenous structures has led some workers to suggest that contractile cells may play an important role in the phenomenon of variable tensility and to call for a re-evaluation of the whole MCT concept. This contribution summarises present information on MCT and appraises the argument implicating muscle in its unique mechanical behaviour. It is concluded that there is no evidence that the variability of the passive mechanical properties of any mutable collagenous structure is due to muscle.
The effect of stimulus features on the visual orienting behaviour of the salamanderPlethodon jordani
Authors: Schülert Niklas , Dicke Ursula 
Published: April 2021

SUMMARYThe effects of the visual features of prey-like objects on the orienting behaviour of the salamander Plethodon jordani were studied. Two stimuli (cricket dummies, rectangles), moving in opposite directions, were presented simultaneously on a computer screen. They differed in size, contrast, velocity and movement pattern of the entire body or the body appendages. Size and velocity appeared to be the dominant features; shape was of lesser importance. Contrast and movement pattern were of intermediate importance and local motion of little importance. This rank order was the same when the probability of a response to the different stimuli was estimated by means of the maximum-likelihood method. Cluster analysis revealed that in all animals stimuli could be grouped into five clusters. Among individuals, the rank order of stimuli was similar for high- and low-ranking stimuli and varied for those of intermediate rank; stimuli could be grouped into 3–5 clusters. Our findings favour the view that, in amphibians, prey recognition is guided by a number of visual features acting either alone or in combination and depending on internal motivational or attentional states and individual experience.Movie available on-line: http://www.biologists.com/JEB/movies/jeb3864.html.
Whole-body hyperthermia-induced thermotolerance is associated with the induction of Heat Shock Protein 70 in mice
Authors: King Yueh-Tsu , Lin Chih-Sheng , Lin Jyh-Hung , Lee Wen-Chuan 
Published: April 2021

SUMMARY
Molecular mechanisms of whole-body thermotolerance (WBT) in mammals have not been investigated thoroughly. The purpose of this study was to assess the induction of the 70 kDa heat shock protein (HSP70) and antioxidant enzyme activity in animal WBT, which was induced by whole-body hyperthermia (WBH) in mice. As a preconditioning treatment, WBH was applied to mice to induce WBT. Synthesis of inducible HSP70 (HSP70i) and quantification of its increased level in liver were investigated by one- and two-dimensional polyacrylamide gel electrophoresis and immunoblotting. HSP70i synthesis in mice liver was induced by non-lethal WBH (41°C, 30 min). When compared to control animals, the level of liver HSP70i increased substantially (by 3.6-fold; P&lt;0.0001). When exposed to 30 min of hyperthermia preconditioning, and after recovery for 48 h, the survival rate was 88.2 %, which was significantly higher than that of the control group (37.5 %; P&lt;0.01). Moreover, the survival rate of animals subjected to preconditioning for 15 min was 72.2 %, which was also significantly higher than that of the control group (P&lt;0.05). In contrast, the survival rate of animals subjected to preconditioning for 45 min was 63.5 %, which was not different from the control group. Nonetheless, the protection index of the group subjected to 15 min and 30 min of preconditioning was 1.93 and 2.37, respectively. Furthermore, to assess their contributions to WBT, the activities of antioxidant enzymes were also measured. After 48 h of recovery in preconditioned animals, hepatic antioxidant enzyme activities, including superoxide dismutase, catalase and glutathione peroxidase, had not changed significantly. To study the molecular mechanism of WBT, we successfully developed a mouse model and suggest that, rather than the activities of antioxidant enzymes, it is HSP70i that has a role to help animals survive during severe heat stress.
Osmoregulation in Some Freshwater Prawns
Authors: Parry Gwyneth 
Published: April 2021

ABSTRACT
A freshwater prawn, Palaemonetes antennarius, from Italy, is shown to have a different level of salt concentration in the blood and urine compared with that of the brackish water P. varians and Palaemon longirostris in Britain. Although this prawn lives in fresh water the urine is isosmotic with the blood and is produced at a rate of about 2 % body weight/hr. An uptake of salts from a very dilute medium has been demonstrated in salt-depleted animals.
Motoneuron Responses to Visual Stimuli in Oncopeltus Fasciatus Dallas
Authors: Chapple William D. 
Published: April 2021

ABSTRACT
Tonic discharges of homologous units in the left and right metathoracic leg nerves in response to increases and decreases in light intensity were observed. Periodic variations in the frequencies of these units was shown to be related to leg movement and at a frequency appropriate for walking. The intensity and duration of discharge of these units was related to the change in light intensity and the frequency of stimulation. The unit of one side normally fired at a higher frequency than that of the other. This was separate from the asymmetry produced by placing the animal in a rotating drum with a single 55° stripe. In this case, clockwise movement of the stripe produced a higher frequency discharge on the left side, while a counterclockwise movement reversed the frequency ratio. Units in the connectives appeared to trigger this discharge.
Motor Patterns During Flight and Warm-Up in Lepidoptera
Authors: Kammer Ann E. 
Published: April 2021

ABSTRACT
The patterns of muscle activity during warm-up were compared to those of flight. In the skipper Hylephila phylaeus and in the hawk moths Celerio lineata and Mimas tiliae the intervals between bursts of muscle potentials are the same as the wingbeat periods of flight at the same thoracic temperature, and the burst length is the same as in flight. In saturniids the period and burst length are both shorter during wing-vibrating than during flight. During wing-vibrating the amplitude of the wing movement is small, and some of the muscles which are antagonists in flight are active simultaneously. In Hylephila phylaeus and Celerio lineata there is a phase change between some synergistic muscles, while some antagonistic pairs retain the phase relationships of flight. During wing-vibrating in Mimas tiliae and in saturniids all the motor units sampled were active at the same time. In M. tiliae a variety of phase relationships intermediate between those of wing-vibrating and flight were observed, including a case of ‘relative co-ordination’ between motor units in the mesothorax. The results exclude the possibility that a single pace-making centre drives the motor neurons in the flight pattern. A model of the central nervous interactions which generate the observed motor patterns is proposed. It is postulated that a small group of positively coupled neurons produces bursts of impulses at the wingbeat frequency and that these groups interact to generate the phase relationships seen during warm-up and flight.
Sodium regulation in the larvae ofChironomus dorsalis(Meig.) andCamptochironomus tentans(Fabr.): the effect of salt depletion and some observations on temperature changes
Authors: Wright D.A. 
Published: April 2021

ABSTRACTSodium regulation was studied in fourth instar larvae of Chironomus dorsalis and Camptochironomus tentans. Both maintain a body sodium level well above that of the surrounding medium. The haemolymph contains approximately 90 % of total body sodium and approximates to a single compartment freely exchanging sodium with the external medium. The anal papillae play a primary role in sodium regulation, the gut being of secondary importance.Sodium regulation in both species is comparatively insensitive to alterations in acclimatization temperature.C. dorsalis and C. tentans are capable of maintaining sodium balance in media containing 10 μmole Na and 25 μmole Na respectively.When exposed to several changes of distilled water, C. tentans is capable of reducing sodium loss by elaboration of a more dilute urine. This is apparently, supplemented by a reduction in the permeability of the body surface. Activation of sodium uptake in both species is comparatively sluggish, with influx reaching a maximum only after the loss of &gt; 30 % body sodium.
Orientation of Demagnetized Bees
Authors: Gould James L. , Kirschvink J. L. , Deffeyes K. S. , Brines M. L. 
Published: April 2021

ABSTRACT
The orientation of honey bee dances is affected by the earth’s magnetic field. Honey bees possess localized, well-oriented, stable and superparamagnetic domains of magnetite. Four lines of evidence suggest that the superparamagnetic domains of bees are more likely to be involved in magnetic field detectors than the stable domains. (1) Although the stable domains vary widely in size and number between bees, approximately 2× 108 superparamagnetic domains are found reliably in all bees, and are restricted to the relatively narrow size range of 300– 350 Å. This suggests that the superparamagnetic domains are more likely to have a biological function. (2) Behavioural observations of dances in null fields are difficult to reconcile with a stable-domain detector but are clearly predicted by many superparamagnetic detector models. (3) When honey bees are demagnetized, their ability to orient to the earth’s field is unaffected. This suggests that the detector either utilizes the superparamagnetic domains or depends on aligned anisotropic stable domains processed without regard to magnetic polarity. (4) Bees that have only superparamagnetic domains are able nevertheless to orient to the earth’s magnetic field, a phenomenon which indicates that permanent domains may not be required for detection.
Neural Control of Radular Retractor Muscles of the Pulmonate Snail, Planorbarius Corneus (L.): Functional Anatomy and Properties of Neuromuscular Units
Authors: Brace R. C. , Quicke D. L. J. 
Published: April 2021

ABSTRACT
The paired supralateral radular retractor muscles of Planorbarius are innervated by eight (four pairs) of buccal motoneurones. Each motoneurone supplies both muscles, the ipsi- and contralateral motor responses being similar, and identical to those produced by its contralateral partner. This arrangement apparently secures equivalence of motor output to the two muscles, irrespective of discrepancies in spiking between homologous motoneurones across the midline, and relates to the strong mechanical linkage between the muscles exerted by the radula. The neuromuscular units are essentially non-overlapping, have properties which range from tonic to phasic, and may act independently providing the flexibility in control required of bifunctional muscles participating in both tensing and retraction of the radula during each feeding cycle.
Coordinated Excitation of Flexor Inhibitors in the Crayfish
Authors: Uyama Chikao , Matsuyama Takashi 
Published: April 2021

ABSTRACT
In isolated abdominal nerve cords of crayfish, the medial or lateral giant axons were stimulated at a position just rostral to the first abdominal ganglion. Recordings of the impulse sequences of the flexor inhibitor (FI) were made from the anterior five ganglia, three ganglia at a time.
In 20% of our preparations, one giant axon impulse caused one to four FI impulses in every abdominal third root. An equal number of FI impulses were usually produced by each abdominal ganglion for any given stimulation.
The earliest FI impulse was observed at the third root of the fourth ganglion. FI impulses occurred with increasing latencies rostrally and caudally from the fourth ganglion.
The FI responses to medial and lateral giant axons stimulation were essentially equivalent.
FI impulses were recorded from the rostral three abdominal ganglia, while the caudal ganglia were cut off one after another from the sixth to the third ganglion. Little change was noted until after the removal of the fourth ganglion, which usually caused all FI impulses to disappear.
From these experimental results, we propose a model of central mechanisms for FI excitation.
Pharmacological Analysis of A Monosynaptic Reflex in the Cockroach, Periplaneta Americana
Authors: Carr Catherine E. , Fourtner Charles R. 
Published: April 2021

ABSTRACT
The monosynaptic connexion between the trochanteral hairplate afferents and the motoneurone Dg was investigated pharmacologically. Electrical stimulation of the hairplate produced a 1:1 reflex activation of Ds which was blocked by saline containing 50 mM-Mg2+. Changes in the hairplate-to-DS reflex and in the tonic activity of DS were monitored during perfusion of drugs known to affect cholinergic transmission. The reflex response was blocked by cholinergic antagonists (atropine, j-tubocurarine, a-bungarotoxin, hexamethonium, decamethonium and TMA); and by an inhibitor of ACh synthesis (hemicholinium-3) ;it was blocked and desensitized by agonists (carbachol and nicotine) and depolarized and blocked by an AChE inhibitor (eserine). These results are consistent with the hypothesis that ACh is a sensory transmitter in the insect CNS.
Connexions Between A Movement-Detecting Visual Interneurone and Flight Motoneurones of A Locust
Authors: Simmons Peter 
Published: April 2021

ABSTRACT
Both of the descending contralateral movement detector (DCMD) neurones of Schistocerca americana gregaria, which respond to stimulation of the contralateral eye or to loud noises, mediate excitatory postsynaptic potentials in most ipsilateral flight motoneurones.
Asymmetric Transfer Hydrogenation of (E)-2-[1,2,6,7-Tetrahydro-8H-indeno[5,4-b]furan-8-ylidene]acetaldehyde Using Polymer-Supported Chiral Pyrrolidine Catalyst
Authors: Haraguchi Naoki , Watanabe Rina , Itsuno Shinichi , Ochiai Hidenori , Nishiyama Akira 
Published: April 2021

Abstract
The asymmetric transfer hydrogenation of α,β-unsaturated aldehyde with Hantzsch ester catalyzed by polymer-supported chiral pyrrolidine organocatalyst was achieved. The effects of the pyrrolidine substituents and linkage configuration on the catalytic performance were examined in detail. We found that the polymer-supported cis-type chiral pyrrolidine organocatalysts showed high enantioselectivities (up to 99.9%) compared with the corresponding trans analogs and monomers in the reaction. The recovered catalyst was reused without any loss of the catalytic activity.
Frequency of early postoperative adverse events (AEs) in adult patients undergoing elective neurosurgical intervention at tertiary care center in Pakistan
Authors: Chandio Mansoor , Shafiq Faraz , Enam Ather 
Published: April 2021

Objective: The postoperative period is critical in neurosurgical patients, where the incidence of postoperative AEs is significantly high. Most of events occurs during recovery phase and has got relation to anaesthetic management. The objective of study was to determine frequency of early AEs in elective neurosurgical patients.
Methods: This cross sectional study was conducted at our tertiary care center. The duration of study was one year, from August 2017-July 2018. The data was collected using predesigned proforma. The assessment was done on arrival in recovery room (T1) and then at forty five minutes (T2), twenty-fourth hour (T3) and forty-eighth hour (T4) postoperatively.
Results: Total ninety-five patients were included. Overall, five hundred and forty AEs were recorded at T1, T2, T3 and T4. Anaesthesia related events like pain, postoperative sore throat, hoarseness, shivering and hypothermia were the commonest (73%). There was a gradual decline in incidence of these events over period of 48 hours. There was no effect of age, sex, BMI and blood loss on incidence of AEs.
Conclusions: Postoperative pain, PONV and shivering were frequently reported AEs. We did not identify the impact of age, sex, BMI, comorbid or type of surgery in terms of having these events.
doi: https://doi.org/10.12669/pjms.37.4.3501
How to cite this:Chandio M, Shafiq F, Enam SA. Frequency of early postoperative adverse events (AEs) in adult patients undergoing elective neurosurgical intervention at tertiary care center in Pakistan. Pak J Med Sci. 2021;37(4):939-944. doi: https://doi.org/10.12669/pjms.37.4.3501
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Diagnostic, management and nursing challenges of less common dementias: Parkinsonian dementias and Huntington's disease
Authors: Davis Laura , Dening Tom 
Published: April 2021

Background: Although most cases of dementia are caused by Alzheimer's disease or vascular dementia, around 10-15% of cases are due to other disorders, including dementias with Parkinsonian features, Huntington's disease, frontotemporal dementia, human immunodeficiency virus (HIV), and alcohol. Aims: These less common dementias are important as they may have differing clinical features and require different approaches to diagnosis and management. This paper seeks to provide relevant information for nurses about symptoms, diagnosis and management of some of the less common dementias. Methods: This is one of two connected papers, and provides a clinical overview of Parkinsonian dementias and Huntington's disease. It provides a narrative, rather than systematic, review of the literature. Findings: Parkinsonian dementias comprise Parkinson's disease dementia, dementia with Lewy bodies and so-called Parkinson's-plus syndromes (multi-system atrophy, progressive supranuclear palsy, and corticobasal degeneration). Huntington's disease is an inherited neuropsychiatric condition. Each has a distinctive clinical picture, with combinations of cognitive, neuropsychiatric and neurological symptoms but approaches to treatment and care are essentially supportive. Conclusions: Nurses have an essential role in supporting people with dementia, as well their families and carers, throughout the course of dementia from diagnosis to end of life care. They are often best placed and have the necessary skills to create appropriate care plans and to provide care management.
Effect of community antiretroviral therapy on treatment outcomes among stable antiretroviral therapy patients in Nigeria: A quasi experimental study
Authors: Dakum Patrick , Ajav-Nyior Juliet , Attah Timothy A. , Kayode Gbenga A. , Gomwalk Asabe , Omuh Helen , Ibrahim Halima , Omozuafoh Mercy , Alash’le Abimiku , Mensah Charles , Oluokun Young , Akolawole Franca 
Published: April 2021

ObjectivesThis study evaluates the effect of Community Anti-retroviral Groups on Immunologic, Virologic and clinical outcomes of stable Antiretroviral Therapy patients in Nigeria.MethodA cohort of 251 eligible adults (≥18 years) on first-line ART for at least 6 months with CD4 counts >200 cells/mm3 and viral load <1000 c/ml were devolved from 10 healthcare facilities to 51 community antiretroviral therapy groups. Baseline immunologic, virologic and clinical parameters were collected and community antiretroviral therapy group patients were followed up for a year after which Human Immunodeficiency Virus treatment outcomes at the baseline and a year after follow-up were compared using paired sample t-test. All the analyses were performed in STATA version 14.ResultOut of the 251 stable antiretroviral therapy adults enrolled, 186 (75.3%) were female, 52 (22.7%) had attained post-secondary education and the mean age of participants was 38 years (SD: 9.5). Also, 66 (27.9%) were employed while 125 (52.7%) were self-employed and 46(19.41%) unemployed. 246 (98.0%) of the participants were retained in care. While there was no statistically significant change in the CD4 counts (456cells/mm3 vs 481cells/mm3 P-0.489) and Log10viral load (3.54c/ml vs 3.69c/ml P-0.359) after one year of devolvement into the community, we observed a significant increase in body weight (60.8 vs 65, P-0.01).ConclusionThis study demonstrates that community antiretroviral therapy has a potential of maintaining optimum treatment outcomes while improving adherence and retention, and reducing the burden of HIV treatment on the health facility. This study provides baseline information for further research and vital information for HIV program implementers planning to decentralize the management of stable antiretroviral therapy clients.
Pensar la (teoría de la) educación, desde la tecnología de nuestro tiempo
Authors: García del Dujo Ángel , Vlieghe Joris , Muñoz-Rodríguez José Manuel , Martín-Lucas Judith 
Published: April 2021

En (teoría de la) educación necesitamos abordar cuanto antes una pregunta: ¿Cómo hacer y pensar la educación en consonancia con las características, exigencias y oportunidades, de esta época digital? A este respecto, después de referenciar los derroteros que en este campo viene siguiendo la investigación pedagógica y la práctica educativa, se plantean en el cuerpo del artículo tres cuestiones – modos de ser, de experienciar el mundo y de construir conocimiento en un sujeto cuya relación con el entorno es mediada por una tecnología cuyo rasgo definitorio viene dado por una pantalla digital – que están demandando otra forma de ver la educación, dicho de otra manera, tres cuestiones directamente afectadas por el nuevo escenario creado por estas tecnologías y que una (teoría de la) educación de nuestro tiempo no puede ignorar, pues sería tanto como no (querer) ver la transición que se está produciendo en las formas de pensar y hacer educación; de alguna manera, sobre ellas descansa y pivota una (teoría de la) educación acorde con este nuestro tiempo digital. El artículo termina con un elenco de preguntas de orden diverso, epistemológico, ontológico y metodológico, pero también ético y politico, estrechamente entrelazadas, que dejan entrever la conveniencia y necesidad de reorientar la reflexión en este campo, al tiempo que conforman un programa de investigación; preguntas con potencialidad suficiente para reorientar la investigación en (teoría de la) educación, inluido el propio concepto y sentido de educar y ser educado.
PERANCANGAN MAXIMUM POWER POINT TRACKING PADA PEMBANGKIT LISTRIK TENAGA BAYU MENGGUNAKAN FOUR SWITCH BUCK BOOST CONVERTER DENGAN METODE P&O-ORB
Authors: Effendy Machmud , Syahputra Rosyadi Nur , Hidayat Khusnul 
Published: April 2021

MPPT (maximum power point tracking) merupakan cara untuk memaksimalkan daya keluaran pada pembangkit listrik tenaga bayu (PLTB). Sistem MPPT pada PLTB terdiri dari DC-DC converter dan metode kontrol. Pada penelitian ini, sistem MPPT menggunakan Four Switch Buck Boost (FSBB) converter, dimana converter ini memiliki polaritas tegangan yang sama antara input dan output, ripple tegangan rendah, dan efisiensi daya lebih besar dibandingkan dengan Buck Boost Converter. Metode kontrol yang digunakan adalah Perturb and Observe (P&O)- ORB (Optimum Relations-Based) yang memiliki tingkat osilasi lebih rendah dan efisiensi lebih tinggi dibandingkan dengan metode P&O.Sistem MPPT disimulasikan menggunakan software PSIM untuk mengetahui performa P&O-ORB dan FSBB converter. Evaluasi kinerja P&O-ORB dan FSBB diuji dalam kondisi kecepatan angin 5 m/s. Hasil simulasi menunjukkan FSBB memiliki tingkat kesalahan yang lebih kecil daripada Buck Boost yaitu 0,02%. Dan sistem MPPT dengan metode P&O-ORB memiliki tingkat efisiensi yang tinggi mencapai 98,01 %.