bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Temperature on a Voltage-Sensitive Electrical Synapse in Crayfish
Authors: Heitler William J. , Edwards Donald H. 
Published: April 2021

ABSTRACT
The effects of temperature on transmission through the voltage-sensitive giant motor synapse (GMS) were investigated in crayfish both experimentally and in computer simulation. The GMS is part of the fast reflex escape pathway of the crayfish and mediates activation from the lateral giant (LG) command neurone to the motor giant (MoG) flexor motoneurone. The investigation was motivated by an apparent mismatch between the temperature sensitivity of the activation time constant of the GMS, with a Q10 reported to be close to 11, and that of the active membrane properties of LG and MoG, which are thought to have Q10 values close to 3. Our initial hypothesis was that at cold temperatures the very slow activation of the GMS conductance would reduce the effectiveness of transmission compared with higher temperatures. However, the reverse was found to be the case. Effective transmission through the GMS was reliable at low temperatures, but failed at an upper temperature limit that varied between 12°C and 25°C in isolated nerve cord preparations. The upper limit was extended above 30°C in semi-intact preparations where the GMS was less disturbed by dissection. The results of experiments and simulations both indicate that transmission becomes more reliable at low temperatures because the longer-duration presynaptic spikes are able to drive more current through the GMS into the MoG, which is more excitable at low temperatures. Conversely, effective transmission is difficult at high temperatures because the transfer of charge through the GMS is reduced and because the input resistance of MoG is lowered as its current threshold is increased. The effect of the high Q10 of the GMS activation is to help preserve effective transmission through the synapse at high temperatures and so extend the temperature range for effective operation of the escape circuit.s
Limits to sustained energy intake
Authors: Johnson M. S. , Thomson S. C. , Speakman J. R. 
Published: April 2021

SUMMARY
Laboratory mice (strain MF1) were used to determine whether sustainable rates of energy intake are limited during lactation. Mice raising natural-sized litters (N=71) reached an asymptote in their daily food intake between days 13 and 16 of lactation at 23.1gday−1 and also between litter sizes of 9 and 15 pups (22.8gday−1). A second group of 37 females had their litter sizes manipulated at birth to raise more or fewer offspring than they gave birth to. When the litter size was increased, females did not increase their food intake to match their new litter size. However, when litter size was decreased, females decreased their asymptotic daily food intake during late lactation in relation to the extent of reduction in litter size. Therefore, it appeared that females were limited during late lactation and with large litter sizes. The milk energy exported amounted to 44% of the gross energy intake, and the estimated daily energy expenditure was therefore considerably lower than the sustained energy intake [8.0×RMR(gross), 6.6×RMR(assimilated)], and averaged 3.1×RMR, where RMR is resting metabolic rate. It was not possible to determine whether the apparent limit on sustained energy intake was acting centrally or peripherally because of the asymptotes in both food intake and milk energy output with increasing litter size.
Locomotion in scombrid fishes: visualization of flow around the caudal peduncle and finlets of the chub mackerelScomber japonicus
Authors: Nauen Jennifer C. , Lauder George V. 
Published: April 2021

SUMMARYScombrid fishes are known for high-performance locomotion; however, few data are available on scombrid locomotor hydrodynamics. In this paper, we present flow visualization data on patterns of water movement over the caudal peduncle and finlets (small fins on the dorsal and ventral body margin anterior to the caudal fin). Chub mackerel, Scomber japonicus, ranging in fork length from 20 to 26 cm, swam steadily at 1.2forklengthss−1 in a recirculating flow tank. Small, reflective particles in the flow tank were illuminated by a vertical (xy) or horizontal (xz) laser light sheet. Patterns of flow in the region near the caudal peduncle were measured using digital particle image velocimetry. Patterns of flow along the peduncle and finlets were quantified using manual particle tracking; more than 800 particles were tracked for at least 12ms over a series of tailbeats from each of four fish.In the vertical plane, flow trajectory and flow speed were independent of the position of the finlets, indicating that the finlets did not redirect flow or affect flow speed. Along, above and below the trailing surface of the peduncle, where the finlets were oriented along the peduncular surface, flow was convergent. Along, above and below the leading surface of the peduncle, where the finlets were absent, the flow trajectory was effectively horizontal. The lack of divergent flow on the leading surface of the peduncle is consistent with cross-peduncular flow formed by the lateral motion of the peduncle interacting with convergent flow resulting from forward movement of the body.In the horizontal plane, particles illuminated by the xz light sheet situated approximately 3 mm below the ventral body surface were tracked within the laser light sheet for up to 40ms, indicating strong planar flow. As the peduncle decelerates, the most posterior finlet is frequently at an angle of attack of at least 20° to the incident flow, but this orientation does not result in thrust production from lift generation. Finlet 5 does redirect cross-peduncular flow and probably generates small vortices undetectable in this study. These data are the first direct demonstration that the finlets have a hydrodynamic effect on local flow during steady swimming.
Structure–function relationships of A-, F- and V-ATPases
Authors: Grüber Gerhard , Wieczorek Helmut , Harvey William R. , Müller Volker 
Published: April 2021

SUMMARYIon-translocating ATPases, such as the F1Fo-, V1Vo- and archaeal A1Ao enzymes, are essential cellular energy converters which transduce the chemical energy of ATP hydrolysis into transmembrane ionic electrochemical potential differences. Based on subunit composition and primary structures of the subunits, these types of ATPases are related through evolution; however, they differ with respect to function. Recent work has focused on the three-dimensional structural relationships of the major, nucleotide-binding subunits A and B of the A1/V1-ATPases and the corresponding β and α subunits of the F1-ATPase, and the location of the coupling subunits within the stalk that provide the physical linkage between the regions of ATP hydrolysis and ion transduction. This review focuses on the structural homologies and diversities of A1-, F1- and V1-ATPases, in particular on significant differences between the stalk regions of these families of enzymes.
A sport-physiological perspective on bird migration: evidence for flight-induced muscle damage
Authors: Guglielmo Christopher G. , Piersma Theunis , Williams Tony D. 
Published: April 2021

SUMMARYExercise-induced muscle damage is a well-described consequence of strenuous exercise, but its potential importance in the evolution of animal activity patterns is unknown. We used plasma creatine kinase (CK) activity as an indicator of muscle damage to investigate whether the high intensity, long-duration flights of two migratory shorebird species cause muscle damage that must be repaired during stopover. In two years of study, plasma CK activity was significantly higher in migrating western sandpipers (a non-synchronous, short-hop migrant), than in non-migrants. Similarly, in the bar-tailed godwit (a synchronous, long-jump migrant), plasma CK activity was highest immediately after arrival from a 4000–5000km flight from West Africa to The Netherlands, and declined before departure for the arctic breeding areas. Late-arriving godwits had higher plasma CK activity than birds that had been at the stopover site longer. Juvenile western sandpipers making their first southward migration had higher plasma CK activity than adults. These results indicate that muscle damage occurs during migration, and that it is exacerbated in young, relatively untrained birds. However, the magnitude of the increases in plasma CK activity associated with migratory flight were relatively small, suggesting that the level of muscle damage is moderate. Migrants may avoid damage behaviourally, or have efficient biochemical and physiological defences against muscle injury.
IDENTIFICATION, SEQUENCE AND EXPRESSION OF A CRUSTACEAN CARDIOACTIVE PEPTIDE (CCAP) GENE IN THE MOTHMANDUCA SEXTA
Authors: LOI P. K. , EMMAL S. A. , PARK Y. , TUBLITZ N. J. 
Published: April 2021

SUMMARYThe crustacean cardioactive peptide (CCAP) gene was isolated from the tobacco hawkmoth Manduca sexta. The gene has an open reading frame of 125 amino acid residues containing a single, complete copy of CCAP. Analysis of the gene structure revealed three introns interrupting the coding region. A comparison of the M. sexta CCAP gene with the Drosophila melanogaster genome database reveals significant similarities in sequence and gene structure.The spatial and temporal expression patterns of the CCAP gene in the M. sexta central nervous system were determined in all major post-embryonic stages using in situ hybridization techniques. The CCAP gene is expressed in a total of 116 neurons in the post-embryonic M. sextacentral nervous system. Nine pairs of cells are observed in the brain, 4.5 pairs in the subesophageal ganglion, three pairs in each thoracic ganglion(T1-T3), three pairs in the first abdominal ganglion (A1), five pairs each in the second to sixth abdominal ganglia (A2-A6) and 7.5 pairs in the terminal ganglion. The CCAP gene is expressed in every ganglion in each post-embryonic stage, except in the thoracic ganglia of first- and second-instar larvae. The number of cells expressing the CCAP gene varies during post-embryonic life,starting at 52 cells in the first instar and reaching a maximum of 116 shortly after pupation. One set of thoracic neurons expressing CCAP mRNA shows unusual variability in expression levels immediately prior to larval ecdysis. Using previously published CCAP immunocytochemical data, it was determined that 91 of 95 CCAP-immunopositive neurons in the M. sexta central nervous system also express the M. sexta CCAP gene, indicating that there is likely to be only a single CCAP gene in M. sexta.
Characteristic features and ligand specificity of the two olfactory receptor classes fromXenopus laevis
Authors: Mezler Mario , Fleischer Jörg , Breer Heinz 
Published: April 2021

SUMMARYAmphibia have two classes of olfactory receptors (ORs), class I (fish-like receptors) and class II (mammalian-like receptors). These two receptor classes correspond to the two classes identified in other vertebrates, and amphibians thus provide a unique opportunity to compare olfactory receptors of both classes in one animal species, without the constraints of evolutionary distance between different vertebrate orders, such as fish and mammals. We therefore identified the complete open reading frames of class I and class II ORs in Xenopus laevis. In addition to allowing a representative comparison of the deduced amino acid sequences between both receptor classes, we were also able to perform differential functional analysis. These studies revealed distinct class-specific motifs, particularly in the extracellular loops 2 and 3, which might be of importance for the interaction with odorants, as well as in the intracellular loops 2 and 3, which might be responsible for interactions with specific G-proteins. The results of functional expression studies in Xenopus oocytes, comparing distinct receptor types, support the idea that class I receptors are activated by water-soluble odorants, whereas class II receptors are activated by volatile compounds.
Direct measurement of oxygen partial pressure in a flying bumblebee
Authors: Komai Yutaka 
Published: April 2021

SUMMARYThe gas transport system of a bumblebee was investigated by measuring the oxygen partial pressure PO2 in the wing muscle. In the resting bee, PO2 showed a regular pattern of fluctuation with a typical period of 70–120s. Fluctuations in muscular PO2 were associated with intermittent abdominal pumping. Ventilation by abdominal movements may not be necessary during rest because PO2 is high (8.5–9.2kPa) in the anaesthetised bee. Thermal effects on muscular PO2 were examined by cooling the bee, causing the amplitude of PO2 fluctuations to increase. In most flight experiments, the bee started to fly after elevating muscle PO2 by abdominal pumping; muscle PO2 then decreased at the onset of flight. However, when a flight began without pre-flight ventilation, PO2 increased monotonically. During flight, muscle PO2 reached a mean level (6.36±1.83kPa) that was much higher than the lowest value recorded during discontinuous ventilation during rest. The bumblebee effectively uses abdominal movements to assist in convective gas transport not only during flight but also at rest.
Effect of food shortage on the physiology and competitive abilities of sand martin (Riparia riparia) nestlings
Authors: Brzęk Pawel , Konarzewski Marek 
Published: April 2021

SUMMARYWe examined developmental and behavioural plasticity of sand martin (Riparia riparia) nestlings hand-reared under laboratory conditions. We created six broods of six 4-day-old nestlings and randomly assigned them to one of the two following feeding regimens, each lasting for 3 days: (1) all nestmates fed a similar, limited amount of food (FR nestlings). This simulated synchronous hatching under conditions of food restriction. (2) Half the brood were food-restricted (FR/AL nestlings), and half were fed ad libitum (AL nestlings), as in asynchronously hatched broods with differential food allocation. Under both regimens, food restriction resulted in a reduction in body mass, intestinal mass, pectoral muscle mass, fat reserves, body temperature and resting metabolic rate (RMR). However, it simultaneously triggered a significant increase in intestinal uptake rates of l-proline and locomotor activity, quantified as frequency of crawling into the artificial nest tunnel by individual nestlings. Locomotor activity and intestinal uptake rates of l-proline by FR nestlings were higher than those of FR/AL young, while body temperature and RMR of FR nestlings were lower.We conclude that food-restricted nestlings responded actively to food shortages by upregulating their gut function, reducing the energy costs of maintenance and increasing locomotor activity. These behavioural and physiological responses were strongest in broods of similar-sized FR nestlings, which can be interpreted as an escalation of sibling competition. Thus, developmental and behavioural plasticity may be an important factor in the evolution of sibling rivalry.
Standard metabolic rate at the surface and during trained submersions in adult California sea lions (Zalophus californianus)
Authors: Hurley Jenifer A. , Costa Daniel P. 
Published: April 2021

SUMMARY
The metabolic rate (MR) of four adult California sea lions (Zalophus californianus), two males and two females, was quantified during trained submersion and stationing behavior in laboratory tanks. MR was measured, at rest and for single submersions of increasing duration (1–7 min), by measuring oxygen consumption using open-circuit, indirect calorimetry. Standard MR was measured under conditions defined for basal MR and was found to be 1.9 to 3 times that predicted for terrestrial animals of similar size. Submersion MRs were calculated from the post-submersion oxygen debt and declined to as little as 47 % of standard MR on the longest submersions. This hypometabolic response was proportional to the duration of submersion and was greatest for the maximum duration submersions. Short submersions produced MRs equivalent to measured standard MR. These data suggest that although California sea lions maintain an elevated metabolism under standard conditions, they are capable of reducing their metabolism in response to the needs of diving. Such metabolic flexibility enables sea lions to moderate their oxygen use during diving and to extend their aerobic diving capability.
An unusual case of Adrenocortical Adenocarcinoma with Biochemical Masquerade of Pheochromocytoma
Authors: Ali Muzaffar , Mirza Lubna 
Published: April 2021

Adrenocortical carcinoma (ACC) is a rare malignancy that arises from the adrenal cortex and often presents as adrenal incidentaloma on abdominal scans with rise in the use of imaging modalities. ACC often presents as Cushing’s syndrome or virilization. On the other hand, pheochromocytoma is an adrenal medullary tumor. It is rare for ACC to present as pheochromocytoma even though both may coexist. Moreover, ACC tumors have radiological and histological features suggestive of aggressive nature of the disease.
We present a case of a 65-year-old lady who initially presented with a 3cm left adrenal incidentaloma. All of her adrenal hormones were in normal range. She was lost to follow up for several years and returned with a much enlarged lesion. Biochemical work up showed mildly increased catecholamines and metanephrines suggestive of pheochromocytoma. She didn’t have any signs or symptoms of pheochromocytoma. She was treated with alpha blockers before surgery as a prophylactic measure. Surgical pathology was consistent with the diagnosis of primary adrenal adenocarcinoma. We recommend that adrenal incidentalomas should be followed annually for up to five years as per American association of Endocrinology and the Endocrine Society guidelines to prevent morbidity and mortality in patients.
doi: https://doi.org/10.12669/pjms.37.4.3916
How to cite this:Ali M, Mirza L. An unusual case of Adrenocortical Adenocarcinoma with Biochemical Masquerade of Pheochromocytoma. Pak J Med Sci. 2021;37(4):1241-1243. doi: https://doi.org/10.12669/pjms.37.4.3916
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.
A bioactive compound isolated from Duku (Lansium domesticum Corr) fruit peels exhibits cytotoxicity against T47D cell line
Authors: Fadhilah Khusnul , Wahyuono Subagus , Astuti Puji 
Published: April 2021

Background: Breast cancer is a major health problem for women globally. Many attempts have been promoted to cure cancer by finding new anticancer medicines from natural resources. Despite the richness of biodiversity discovered, there are some natural resources that remain unexplored. Fruit peels of Duku (Lansium domesticum Corr.) are rich with compounds that may have the potential to be developed as anticancer drugs. This study aimed to isolate cytotoxic compounds from the fruit peels of L. domesticum and assess their cytotoxic nature against T47D cells. Methods: Powdered peels were macerated with ethyl acetate and the filtrate was evaporated to give EtOAc extract A. Dried extract A was triturated with n-hexane to give n-hexane soluble fraction B and insoluble fraction C. The cytotoxic nature of these three samples were assessed using MTT assay using T47D cells and doxorubicin as a control. Results: Fraction C that showed the smallest IC50 (25.56 ± 0.64μg/mL) value compared to extract A and fraction B. Fraction C was further fractionated by vacuum liquid chromatography to give 6 subfractions. Subfraction 2 showed a single compound based on thin layer chromatography, and this compound was identified as Lamesticumin A on the basis of its spectroscopic data. Lamesticumin A demonstrated cytotoxic activity against T47D cell lines with an IC50 value of 15.68 ± 0.30µg/mL. Conclusions: Further research is needed to investigate the potential of the natural compound Lamesticumin A derived from L. domesticum fruit peel as an anticancer therapy.
Mechanizmy rynkowe i interwencja państwa w polityce regionalnej Chińskiej Republiki Ludowej
Authors: Świstak Marek 
Published: April 2021

Market Mechanisms and State Intervention in Diversifying the Regional Development of the People’s Republic of China
The article focuses on the importance of market mechanisms and state intervention in the field of regional development policy, in particular on the dominant process of development differentiation. The aim of the article is to verify to what extent market mechanisms are the driving force in China’s regional development policy, and to what extent state intervention is the driving force. It is also important because of the fact that regional policy is an amalgam of the public intervention and presence of market forces, regardless of the country’s political regime. The article identifies the elements that determine the differentiation of regional development due to the operation of market mechanisms and state intervention in China’s regional policy.
Die Entwicklung des Konzepts von Hans-Dietrich Genscher in der bundesdeutschen Entspannungspolitik in den Jahren 1974-1989. Herkunft – Instrumente – Auswirkungen
Authors: Węc Janusz Józef 
Published: April 2021

The Evolution of the Concept of Hans-Dietrich Genscher in the German Détente Policy in the Years 1974-1989. Genesis – Instruments – Impact
The main aim of this article is to present the genesis, instruments and real influence of the concept of the “realistic” détente policy of the German Minister of Foreign Affairs Hans-Dietrich Genscher on the foreign policy of the German federal government in the years 1974-1989. The author formulates a thesis that Genscher’s concept had very significant influence on the program activities of the FDP as well as on the practical foreign policy of the SPD/FDP governments (1974-1982) and CDU/CSU/FDP governments (1982-1989), whereby the year 1985 was an important turning point in this evolution.
Fenomen studiów nad Chinami w Instytucie Bliskiego i Dalekiego Wschodu Uniwersytetu Jagiellońskiego
Authors: Gacek Łukasz , Trojnar Ewa 
Published: April 2021

The Phenomenon of China Studies at the Institute of the Middle and Far East of the Jagiellonian University
Modern China became the phenomenon eagerly investigated by wide circles of observers. This trend is associated with a growing number of academic fields with the Asiatic profile on the level of university education. Such characteristics is completely reflected in studies conducted at the Institute of the Middle and Far East of the Jagiellonian University. The purpose of this research is to comprehend a phenomenon of the current interest in Asia developed in Poland, with an example of China, among students of fields at the Institute with the Chinese profile. In recent years, the Institute of the Middle and Far East of the Jagiellonian University became the largest academic institution in Poland conducting this type of studies in nonphilological fields. Research proved that studies on China match the need of educating persons who both know Chinese and have specific knowledge about this country. Uniqueness of the field of study and created professional chances appeared to be equally important.