bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Air Resistance On the Jumping Performance of Insects
Authors: Bennet-Clark H. C. , Alder G. M. 
Published: April 2021

ABSTRACT
A spring gun was constructed to propel objects at known velocities of between 1 and 4·5 m.s-1. This was used to project insects and various models in a vertical trajectory. By comparing the height attained in air by the insects or models with the height theoretically possible in vacuo, the energy lost against air resistance was observed. Small insects have a higher frontal area to mass ratio than larger ones so have relatively more aerodynamic drag and attain lower heights.
The observed effect may be expressed in terms of the drag coefficient, CD. Fleas and locusts have CD of about 1. Winged flies have CD of about 1·5 which falls to about 1 when the wings are amputated and to about 0·8 when the legs are amputated. Aptery is advantageous in jumping insects.
From experiments with models, it appears that the optimal condition for small jumping insects is that the body should be as compact as possible to reduce the frontal area to mass ratio. Thus dense spherical bodies are favoured. Some species of jumping insect have densities of about 1 mg.mm−3 while some flying beetles and flies have densities between 0·3 and 0·8 mg.mm−3.
The Reynolds number at which the experiments were performed was from 65–205 for fleas up to 740–2340 for locusts. The models operated in similar ranges.
At a velocity which would propel a larger animal to a height of 1 m, fleas weighing 0·4 mg only reach about 0·4 m. At lower initial velocities, proportionately less energy is wasted against air resistance so the jump efficiency is higher. Most fleas jump to a height of about 0·1 m with an efficiency of 0·8 while locusts jump to a height of 0·35 m with an efficiency of over 0·9. Air resistance is thus an important scale effect in jumping insects and provides its own design constraints.
Acid-Base Relationships in the Blood of the Toad, Bufo Marinus
Authors: Boutilier R. G. , Randall D. J. , Shelton G. , Toews D. P. 
Published: April 2021

ABSTRACT
An abrupt increase in ambient CO2 resulted in a marked respiratory acidosis which took place within 30 min. During this time there was a considerable reduction in the difference between arterial blood and inspired gas caused by an increase in ventilations. Prolonged CO2 exposure (24 h) showed that there was some compensation for the acidosis in that plasma bicarbonate concentrations increased substantially. At the same time, however, the of arterial blood always rose so that the net result was usually only a small increase in pH. Upon return to air, the blood was backtitrated along a buffer line elevated above and parallel to that seen during the initial response to hypercapnia. The fall in arterial blood during the early stages of recovery often led to pH values higher than those seen in the untreated animal. After 48 h in air, recovery had gone further with pH and [HCO3−] levels approaching but rarely reaching the pre-exposure values.
Ionic Selectivity of the Calcium Channels in Insect Larval Muscle Fibres
Authors: Yamamoto Daisuke , Washio Hiroshi 
Published: April 2021

ABSTRACT
It is well known that the action potentials of insect muscle fibres are generally Ca-dependent (Washio, 1972; and others). The calcium channels involved in these spikes have recently been shown to pass Na as well as Ca ions in the larvae of the beetle Tenebrio molitor (Yamamoto & Washio, 1979) and in the locust (Mathers & Thesleff, 1979). In this report we examine whether the Ca channels of Tenebrio can pass Li+, NH4+, guanidine, choline and TEA. Li+, NH4+ and guanidine have been shown to negotiate Na channels (Binstock & Lecar, 1969; Hille, 1971, 1972).
Voltage Clamp Studies on Insect Skeletal Muscle
Authors: Yamamoto Daisuke , Fukami Jun-Ichi , Washio Hiroshi 
Published: April 2021

ABSTRACT
Membrane currents in the muscle fibre of larval mealworm, Tenebrio molitor were investigated under voltage-clamp conditions. An initial inward current, a transient outward current and a delayed outward current were distinguished. Increasing external calcium concentration increased the size of the inward current and shifted the reversal potential in a positive direction. The inward current persisted in Na-free media and TTX-saline. However, the current was suppressed by 15 mm-cobalt ions. Therefore, it was concluded that the inward current was carried by calcium ions. Although the inward current was markedly reduced when external sodium was replaced with glucose, it was concluded that the contribution of Na ions to the current was small. Calcium conductance showed voltage and time dependence. The inactivation variable fell below unity with increasing strength of hyperpolarizing prepulses.
Physiology of Water Motion Detection in the Medicinal Leech
Authors: Friesen W. Otto 
Published: April 2021

ABSTRACT
Neuronal activity resulting from stimulation by water waves occurs in ventral nerve cord-body wall preparations of the medicinal leech, Hirudo medicinalis. In segmental nerves, this activity consists of afferent compound action potentials with graded amplitudes resulting from simultaneous action potentials in many small sensory axons. Afferent input impinging on one segmental ganglion activates neuronal activity along much of the ventral nerve cord. Previously identified tactile mechanoreceptors are insensitive to low-amplitude wave stimulation. Touch-cell impulse activity can be evoked by moderate or strong wave stimulation, but these impulses appear to arise near the cell body, not from the peripheral receptor endings. The transduction sites for wave stimulation are localized at or very near the segmental sensilla. Because of their location and modality the receptors were named ‘sensillar movement receptors’ (SMR). S cells (Rohde’s fibre) receive suprathreshold excitatory input during SMR activation without concomitant activity in the tactile mechanoreceptors. The annulus erector motor neurones contralateral to the afferent SMR inflow are inhibited by SMR activation. This inhibition is also observed in ganglia adjacent to the ganglion receiving the afferent input and provides a neuronal basis for reflexive smoothing of the leech body wall. Two neurones in the anterior median packet of segmental ganglia receive powerful synaptic input during SMR activation. One, cell 202, receives 10 mV excitatory potentials while the other, cell 201, receives 10 mV inhibitory potentials.
The Modulatory Action of Dopamine On Crustacean Foregut Neuromuscular Preparations
Authors: Lingle Chris 
Published: April 2021

ABSTRACT
Effects of dopamine (DA) on contractile and electrical properties of decapod foregut neuromuscular preparations were examined. Dopamine produced dramatic increases in nerve-evoked contractions and, in particular muscles, contractures and spontaneous contractions. These effects were observed at concentrations as low as 5 × 10−9 M-DA. The DA-produced enhancement of nerve-evoked contractions was associated with an increase in amplitude of excitatory junctional potentials (EJPs). The increase in EJPs resulted in part from an increase in muscle fibre membrane resistance that was particularly prominent over depolarized membrane potentials. A presynaptic action of dopamine cannot be as yet excluded. In fibres from the muscle in which dopamine produced a contracture, dopamine also produced a depolarization. In fibres from the muscle in which dopamine activated spontaneous contractions, dopamine also produced spontaneous rhythmic action potentials. Dopamine also accelerated the half-time of muscle relaxation following muscle contraction
Fish Branchial Na+/NH4+ Exchange is Via Basolateral Na+-K+-Activated ATPase
Authors: Claiborne J. B. , Evans David H. , Goldstein Leon 
Published: April 2021

ABSTRACT
Krogh (1939) first proposed that freshwater organisms extract needed Na+ in exchange for to maintain near-electroneutrality across the skin or gills. Maetz & Garcia-Romeu (1964) provided an indirect demonstration of exchange in the goldfish (Carassius auratus) by showing that injected NH4C1 stimulated Na+ uptake, but addition of NH4C1 to the freshwater inhibited Na+ uptake. They proposed that exchange was apical (on the mucosal surface of the transporting epithelium, facing the fresh water) and that blood NH3 entered the basolateral surface of the cell, combined with a proton generated by the carbonic anhydrase hydration of CO2 (and the subsequent dissociation of carbonic acid), and left the cell in exchange for Na+. The role for carbonic anhydrase was indicated by their finding that injection of acetazolamide inhibited Na+ uptake. Subsequently, Kerstetter, Kirschner & Rafuse (1970) demonstrated that acetazolamide injection inhibited the influx of Na+ into the irrigated gills of the trout (Salmo gairdneri). However, ammonia efflux was not significantly inhibited, while acid efflux was. They concluded that Na+/H+, rather than exchange, occured at the apical surface. More recent evidence supporting the model for basolateral uptake of NH3 and apical exchange was presented by Payan (1978). He used the isolated, perfused, head of the trout (Salmo gairdneri) and showed that: (1) addition of amiloride to the solution irrigating the gills inhibited both Na+ influx and ammonia efflux, (2) acetazolamide added to the perfusate inhibited ammonia efflux, and (3) reduction in the NH3 concentration of the perfusate (by lowering pH) inhibited ammonia efflux as well as Na+ influx. Furthermore, addition of ouabain to the perfusate inhibited ammonia efflux, presumably because Na+-K+-activated ATPase at the basolateral surface mediates the final transfer of Na+ into the serosal medium, and is ultimately limiting in the regulation of apical exchange.
Mechanisms of Acid Extrusion by Two Marine Fishes: The Teleost,Opsanus Beta, and the Elasmobranch,Squalus Acanthias
Authors: Evans David H. 
Published: April 2021

ABSTRACTRates of efflux of H+ and ammonia from a marine teleost and an elasmobranch were measured. Hypercapnia stimulated H+; efflux from both species, stimulated ammonia efflux from the elasmobranch, and inhibited ammonia efflux from the teleost. In both species the H+; and ammonia efflux were predominantly across the branchial epithelium. In Na+-free sea water, the H+ efflux from both species was completely abolished and the ammonia efflux was inhibited by approximately 50%. Injection of an acid load stimulated H+; efflux, which continued for 2-5 h until more than the injected acid load was excreted. It therefore appears that injection of an acid load also produces a metabolic acid load which must be excreted. The H+ efflux from mineral/metabolic acidotic fish is entirely branchial and dependent upon external Na+. The data support the conclusion that marine teleosts and elasmobranchs possess branchial Na+/NH4+ and Na+/H+; ionic exchange mechanisms and that Na+/H+; exchange plays a major role in the response to acidosis in both groups. The possible evolution of these ionic exchange systems is discussed.
Osmotic Tolerance of Ca-Dependent Excitability in the Marine Ciliate Paramecium Calkinsi
Authors: Deitmer Joachim W. , Machemer Hans 
Published: April 2021

ABSTRACT
The electrical membrane properties of the marine (brackish-water) ciliate Paramecium calkinsi were investigated under constant-current and voltage-clamp conditions, using two intracellular microelectrodes. The action potential and membrane currents were extremely tolerant to changes in the salinity of the bathing medium. Current-voltage relationships exhibited a moderate inward-going rectification of the membrane upon hyperpolarization, and a prominent outward-going rectification upon depolarization of the membrane. Ion substitution experiments showed that the electrically excitable response is a graded Ca2+-action potential, similar to that found in freshwater ciliates.
Energetics and mechanics of terrestrial locomotion. III. Energy changes of the centre of mass as a function of speed and body size in birds and mammals
Authors: Heglund N. C. , Cavagna G. A. , Taylor C. R. 
Published: April 2021

ABSTRACTThis is the third in a series of four papers examining the link between the energetics and mechanics of terrestrial locomotion. It reports measurements of the mechanical work required (ECM,tot) to lift and reaccelerate an animal’s centre of mass within each step as a function of speed and body size during level, constant average speed locomotion. A force platform was used in this study to measure ECM,tot for small bipeds, quadrupeds and hoppers. We have already published similar data from large animals. The total power required to lift and reaccelerate the centre of mass (ĖCM,tot) increased nearly linearly with speed for all the animals. Expressed in mass-specific terms, it was independent of body size and could be expressed by a simple equation :where ĖCM,tot/Mb has the units of W kg−1 and vg is speed in m s−1.Walking involves the same pendulum-like mechanism in small animals as has been described in humans and large animals. Also, running, trotting and hopping produce similar curves of ECM,tot as a function of time during a stride for both the small and large animals. Galloping, however, appears to be different in small and large animals. In small animals the front legs are used mainly for braking, while the back legs are used to reaccelerate the Centre of mass within a stride. In large animals the front and hind legs serve to both brake and reaccelerate the animal; this difference in mechanics is significant in that it does not allow the utilization of elastic energy in the legs of small animals, but does in the legs of large animals.
Electrical Properties of Fibres from Stridulatory and Flight Muscles of a Tettigoniid
Authors: Josephson Robert K. , Stokes Darrell R. 
Published: April 2021

ABSTRACTThe mesothoracic dorsal longitudinal muscle (DLM) of the katydid Neoconocephahts robustas is used in stridulation and flight; the metathoracic DLM is used in flight only. The DLM’s in the two segments have radically different maximum operating frequencies, 200 Hz for the mesothoracic muscle during stridulation and 20 Hz for the metathoracic muscle during flight. Cable analysis was used to determine the passive electrical properties of mesothoracic and metathoracic DLM fibres. Fibres in the two segments are of similar diameter and have similar sarcoplasmic resistivity. The apparent membrane resistance is lower, the apparent membrane capacitance higher, and the time constant shorter in mesothoracic fibres than in the metathoracic homologues. The depolarization evoked by neural stimulation in both mesothoracic and metathoracic fibres is principally an excitatory junctional potential (e.j.p.) with little or no contribution from voltage-dependent, inward current channels. At shqrt interstimulus intervals the second e.j.p. of a pair is reduced in amplitude relative to the first e.j.p. The period of e.j.p. depression is shorter in mesothoracic than in metathoracic fibres. It is suggested that the faster recovery of e.j.p.’s in mesothoracic fibres is due to more rapid recovery of the transmitter release mechanism in their motorneurones. In mesothoracic but not metathoracic fibres the voltage response to large depolarizing currents is usually oscillatory, and the recovery of e.j.p. amplitude as a function of time in paired shock experiments is sometimes oscillatory. The oscillation frequency is 250–300 Hz (35 °C) which is higher than the natural operating frequency of the muscle.
Electrical Activity and Structure of Retinal Cells of the Aplysia Eye: I. Secondary Neurones
Authors: Jacklet Jon W. , Schuster Lesley , Rolerson Celine 
Published: April 2021

ABSTRACT
Intracellular recordings were made from secondary neurones and photoreceptors of the Aplysia eye concurrently with extracellular recordings from the optic nerve. These cells were injected with Lucifer yellow to reveal their structure after they were typed according to electrical activity. Secondary neurones are described in this paper. All secondary neurones injected with Lucifer yellow were in the outer, non-receptor layer of the retina. Each had an axon in the optic nerve, short dendritic processes on the soma, but no distinct photoreceptive apparatus. Dye coupling between secondary neurones and between secondary neurones and photoreceptors was observed. Secondary neurones had pacemaker potentials and action potentials (APs) correlated 1 :1 with the optic nerve compound action potentials (CAPs) during spontaneous dark and light evoked activity. It is deduced that the secondary neurones are the output neurones of the circadian clock system of the eye. Secondary neurones appear to be electrically coupled to each other and to some photoreceptors, since blocking chemical synapses with high Mg2+ saline did not block the spontaneous or light evoked activities, and antidromic activation of the secondary neurones produced a compound input dependent in amplitude on stimulus voltage. Backfilling the optic nerve with cobalt revealed filled secondary neurones, 2 photoreceptor types and a small non-receptor cell type suggesting that most of these retinal cells have axons in the optic nerve.
Prevalence of Prediabetes and Type-2 Diabetes Mellitus in Cricket Players: Multi-Cricket Clubs Cross Sectional Study
Authors: Meo Sultan Ayoub , Abukhalaf Abdulelah Adnan , Alomar Ali Abdullah , Sami Waqas , Meo Anusha Sultan 
Published: April 2021

Background & Objectives: Sports activities are highly beneficial for improving the human health and reducing the risk of diseases. This cross sectional study aimed to investigate the prevalence of prediabetes and Type-2 diabetes mellitus in cricket players compared to population based non-elite athlete control subjects.
Methods: The present matched cross sectional study was conducted in the Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia during the period October 2019 to February 2020. Initially, 700 volunteer males, (300) cricket players and (400) population based non-elite athlete control subjects were interviewed. After socio-demographic and medical history, (200) nonsmoker cricket players and (300) nonsmoker control subjects were recruited. The age of cricket players was 34 (32-37) years, weight 81 (76-84) kg, height 1.79 (1.74-1.84) meters, and body mass index (BMI) was 25.09 (23.66-26.76) kg/m2. The cricket players have been playing cricket for 4 (3-4) hours per day; 3.50 (3-4) days per week; for the total period of 24 (12-36) months. American Diabetes Association (ADA) based criteria on Glycated Hemoglobin (HbA1c) was used to investigate the prediabetes and Type-2 diabetes mellitus.
Results: In cricket players, the prevalence of prediabetes was 23 (11.5%) and Type-2 diabetes mellitus (T2DM) was 7 (3.5%) compared to population based matched non-elite athlete control subjects the prediabetes was 73 (24.34%) and T2DM was 63 (21.1%) (p=0.001). Among cricket players, there was a 6-folds decrease in T2DM compared to control subjects.
Conclusions: The cricket sports activities decrease the prevalence of prediabetes and Type-2 diabetes mellitus (T2DM) among the cricket players compared to population based matched non-elite athlete control subjects. The study findings demonstrate the urgent need for promoting sports activities, more cricket grounds as a physiological preventive strategy against the global growing diabetes epidemic.
doi: https://doi.org/10.12669/pjms.37.4.4128
How to cite this:Meo SA, Abukhalaf AA, Alomar AA, Sami W, Meo AS. Prevalence of Prediabetes and Type-2 Diabetes Mellitus in Cricket Players: Multi- Cricket Clubs Cross Sectional Study. Pak J Med Sci. 2021;37(4):959-965. doi: https://doi.org/10.12669/pjms.37.4.4128
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.
RELIGIUSITAS SEBAGAI MODAL SOSIAL MAHASISWA E-PRENEUR PRODI SOSIOLOGI AGAMA IAIN KEDIRI
Authors: Silviana Ika 
Published: April 2021

Technological developments have accelerated the transformation of trade patterns in Indonesia. This cannot be denied because of the incessant wave of the industrial revolution 4.0 that has infiltrated to the smallest line of production. The e-commerce system is able to accommodate most all activities of small, medium and large economic actors. In this context, students have begun to realize the important of entrepreneurial skills. This study focuses on portraying a religiosity aspect of e-preneur has been developed at the Sociology of Religion Study Program at IAIN Kediri. Through the phenomenological approach, data mining was carried out on 4 selected informants using observation, interview and documentation methods. By using James Coleman's theory of social capital and the dimensions of religiosity, the following results are obtained: (1) religiosity aspect of e-preneur student is formed through the formation of education and habituation in the family environment, religion-based formal education and Islamic boarding schools; (2) the religious practices of entrepreneurship are carried out through the application of religious values, reflecting on experiences, and determining life goals after graduation; (3) religiosity is used to build social capital in the form of belief in success by applying believed in religious values. (4) The practice of e-preneur religiosity produces 3 attitudes, which consist of independence, realistic (waqi'iyah), and moderation (washathiyah). Perkembangan teknologi mendorong percepatan transformasi pola perdagangan di Indonesia. Hal ini tidak dapat ditolak karena gencarnya gelombang revolusi teknologi 4.0 yang telah menyusup hingga lini terkecil. Sistem e-commerce dapat mewadahi aktivitas pelaku ekonomi kecil, menegah dan atas. Kesempatan ini mulai dilirik oleh kalangan mahasiswa sebagai upaya mengasah kecakapan berwirausaha. Penelitian ini memfokuskan pada potret religiusitas mahasiswa e-preneur Prodi Sosiologi Agama di IAIN Kediri. Melalui pendekatan fenomenologi dilakukan penggalian data pada 4 subyek terpilih dengan metode observasi, wawancara dan dokumentasi. Dengan menggunakan teori modal sosial James Coleman dan dimensi religiusitas didapatkan hasil sebagai berikut: (1) religusitas mahasiswa e-preneur terbentuk melalui landasan pendidikan dan pembiasaan di lingkungan keluarga, pendikan formal berbasis agama dan pesantren. (2) praktik religiusutas berwirausaha dilakukan melalui penerapan nilai agama, merefleksikan pengalaman, dan menentukan tujuan hidup setelah lulus. (3) Religiusitas digunakan untuk membangun modal sosial berupa kepercayaan akan kesuksesan dengan menerapkan nilai-nilai agama yang diyakini. (4) Praktik religiusitas e-preneur menghasilkan 3 sikap yang mencakup kemandirian, realistis (waqi’iyah), dan moderasi (washathiyah).