Effect of Altitude and Duration of Stay on Pulmonary Function in Healthy Indian Males

The study was carried out with the objective to investigate the effect of varying altitude and duration of exposure on blood pressure, heart rate and lung function parameters in healthy Indian soldiers after adopting proper acclimatization schedule. For this purpose 17 soldiers of Indian Army, weight and height matched, were studied after obtaining written consent. Recording of Blood pressure (systolic and diastolic), heart rate and lung function variables (FVC, FEV1, FEV1/FVC%, MVV, FEF25-75%, MEF 25%, MEF 50%, MEF 75%, PEF) were measured at basal (290m), 800m, 3200m (day 10 and day 20) and upon de-induction. Our results demonstrate that with increasing altitude FVC declined, FEV1 did not change and due to these changes FEV1/FVC% increased. Expiratory flow rates including MEF 25%, MEF50% MEF 75%, PEF and mean expiratory flow rate (FEF25-75%) increased upon induction to high altitude. This increase may be due to reduction in air density causing less air resistance which accelerates lung emptying. Though the increase upon induction in all the values was transient and returned to baseline values after de-induction. MVV reflecting respiratory muscle function increased significantly upon induction to altitude in our study and returned to basal values upon de-induction. Understanding respiratory system in mountainous regions and its further correlation with other systems pertaining to acclimatization could help in laying step in unveiling mechanism of human high altitude adaptation

Energy Expenditure and Nutritional Status of Sailors and Submarine Crew of the Indian Navy

Nutritional requirements of sailors and submariners are different from those of ground forces as they work under confined environment as well as due to logistic constraints of cooking and storage of food. Study was conducted for a period of three months at Eastern Naval Command to evaluate nutrient requirements, nutritional status of Indian Navy personnel and adequacy of the existing ration scales. The study volunteers were from crew of two warships (n = 35) and submariners (n = 20) who were attached to their mother ships during time of data collection and offshore during rest of the period. Energy expenditure, nutrient intake, level of nutrients in body, and urinary excretion were measured along with changes in body composition. All variables were analysed before and after three months of nutritional monitoring. Energy expenditure at ship was in the range of 2449-4907 kcal/day with a mean of 3313 + 578 kcal/day, while in the case of submariners, it was 3168 + 282 (2606-3907) kcal/day. The energy intake in the case of sailors and submariners was not different either on shore establishment or at ship. Energy intake was found to be 3518 + 286 kcal/day. The energy contribution from carbohydrates, fats, and protein was 59.9 per cent, 27.8 per cent and 12.3 per cent, respectively. No sign and symptoms of any nutritional deficiency were observed either initially or after three months. Status of micronutrients present in their blood and in their urinary excretions along with body composition were maintained, indicating adequacy of existing ration scales of Indian Navy.Defence Science Journal, 2011, 61(6), pp.540-544, DOI:http://dx.doi.org/10.14429/dsj.61.93

Biochemical Changes in Lowlanders on Descent to Plains after Prolonged Stay at High Altitude-A Cross-sectional Study

The biochemical changes taking place in human subjects following de-induction to plains from high altitude (5700-6100 m) after a prolonged slay of 9-13 months were investigated in 120 soldieri in four groups of 30 each on day 5, 30, 60 and 90 after their descent. One group of soldiers, who were never posted at high altitude served as control. Haemoglobin levels, which were initiall,v hiueh after 5 dnvs of de-induction droooed lo sienificantlv lower levels in the erouo . L ., " . studied on day 60 after de-induction. No clinically abnormal changes were noted in activities of serum enzymes, ie, aspartate aminotransferase, alanine aminotransferase and y-glutamyl transpeptidase. Alanine aminotransferase activity was found significantly elevated in 5-day group (53.1 i0.24 IUII). Cholesterol and triglyceride levels were higher in 30-day group in comparison to groups studied on day 5,60 and 90 after de-induction from high altitude. Activity of glutathione S-transferase was more in groups studied on day 30 and 60 and may he in response to increased demand for detoxification of certain metabolites. Endogenous creatinine clearance was impaired with concomitant increase in serum creatinine levels. The creatinine clearance returned to normal only in group studied on day 90 after de-induction. Testosterone and estradiol levels were within normal physiological limits. However, there was increase in testosterone levels following ds- ~nductionR. esults of this cross-sectional study indicate that it takes 1-3 months after de-induction from high altitude for biochemical parameters to reach normal levels

Zmiany w stężeniu greliny, CCK, GLP-1 i ekspresji receptorów aktywowanych przez proliferatory peroksysomów w szczurzym modelu anoreksji wywołanej przez hipoksję

  Introduction: A high-altitude environment causes appetite loss in unacclimatised humans, leading to weight reduction. Ghrelin, cholecystokinin (CCK), and glucagon like peptide-1 (GLP-1), are gut hormones involved in the regulation of food intake and energy metabolism. The liver is an important site of metabolic regulation, and together with the gut it plays a role in food intake regulation. This study intends to study the timedependent changes occurring in plasma gut hormones, PPARα, PPARδ, and PGC1α, in the stomach and liver during hypoxia. Material and methods: Male Sprague Dawley rats were exposed to hypobaric hypoxia in a decompression chamber at 7620 m for different durations up to seven days. Results: Hypoxia increased circulating ghrelin from the third day onwards while CCK and GLP-1 decreased immediately. An increase in ghrelin, ghrelin receptor protein levels, and GOAT mRNA levels in the stomach was observed. Stomach cholecystokinin receptor (CCKAR), PPARα, and PPARδ decreased. Liver CCKAR decreased during the first day of hypoxia and returned to normal levels from the third day onwards. PPARα and PGC1α expression increased while PPARδ protein levels reduced in the liver on third day. Conclusion: Hypoxia alters the expression of ghrelin and ghrelin receptor in the stomach, CCKAR in the liver, and PPAR and its cofactors, which might be possible role players in the contribution of gut and liver to anorexia at high altitude. (Endokrynol Pol 2015; 66 (4): 334–341)    Wstęp: Przebywanie na dużej wysokości powoduje utratę apetytu u osób do tego nieprzystosowanych i prowadzi do redukcji masy ciała. Grelina, cholecystokinina (CCK) i peptyd glukagonopodobny 1 (GLP-1) są hormonami przewodu pokarmowego biorącymi udział w regulacji przyjmowania pokarmu i metabolizmu energii. Wątroba stanowi ważne miejsce regulacji metabolicznej i razem z jelitem spełnia istotną funkcję w regulacji przyjmowania pokarmu. Niniejsze badanie miało na celu ocenę zmian zależnych od czasu w stężeniu hormonów przewodu pokarmowego oraz ekspresji PPARα, PPARδ oraz PGC1α w żołądku i wątrobie występujących podczas hipoksji. Materiał i metody: Szczury Sprague Dawley płci męskiej poddano działaniu hipoksji hipobarycznej w komorze dekompresyjnej na wysokości 7620 m. Pobyty w komorze różniły się czasem trwania, do maksymalnie 7 dni. Wyniki: Hipoksja podwyższała stężenie krążącej greliny od trzeciego dnia pobytu z komorze do końca jego trwania, podczas gdy stężenia CCK i GLP-1 uległy natychmiastowemu obniżeniu. Zaobserwowano podwyższenie stężenie greliny, białka receptora greliny i GOAT mRNA w żołądku. W żołądku ekspresja receptorów cholecystokininy (CCKAR), PPARα i PPARδ uległy obniżeniu. stężenie wątrobowego CCKAR uległ obniżeniu pierwszego dnia wystąpienia hipoksji, powrócił do prawidłowego stężenia trzeciego dnia i pozostał prawidłowy do końca pobytu w komorze. Ekspresje PPARα i PGC1α wzrosły, podczas gdy stężenie białka PPARδ uległo obniżeniu w wątrobie. Wnioski: Hipoksja zmienia ekspresję greliny oraz receptora greliny w żołądku, CCKAR w wątrobie i PPAR oraz jego kofaktory, które mogą odgrywać rolę w przyczynianiu się jelit i wątroby do anoreksji przy przebywaniu na dużej wysokości. (Endokrynol Pol 2015; 66 (4): 334–341)

Influence of Altitude on Pulmonary Function

Variation in lung function at high altitude (HA) impacts the working capacity of individuals and may predispose body towards hypoxia induced illness. So, we investigated the changes in pulmonary function of healthy human male volunteers belonging to two different ethnicities i.e. Indian and Kyrgyz. Twenty, age and BMI matched, volunteers (Indian=10 and Kyrgyz=10) were recruited for the study. Measurement for pulmonary functions (FVC, FEV1, FEV1/FVC ratio, PEF, FEF 25-75%, MEF 25%, MEF 50%, MEF 75%, MVV) were performed on each individual at basal (800 m) and high altitude (4,111 m) on day 3,7,14 and 21. Results indicate that Kyrgyz has comparatively higher FVC, FEV1, PEF and MVV values and lower FEV1/FVC ratio upon altitude induction than those of Indian counterparts. Mid expiratory flow FEF25-75% was significantly increased in Kyrgyz upon altitude induction indicate more proficient lung emptying while only moderate increase at day 7 in Indian. MEF25% was significantly increased in Kyrgyz, while no change is observed in Indians at high altitude which indicates that 75% of lung emptying through small airways is better in Kyrgyz. MEF 50% and MEF 75% increased with altitude in both groups. For MVV, the maximum increase was ~17% in Indian at HA14 (p<0.01) and in Kyrgyz ~33% (p<0.001) at HA14 as compared to basal. Difference in lung function response observed, indicates that Kyrgyz has better pulmonary dynamics during altitude exposure as compared to Indian counterparts. The varied result observed may be due to different ethnic origin of the groups

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV

Probing effective field theory operators in the associated production of top quarks with a Z boson in multilepton final states at root s=13 TeV

Peer reviewe

Observation of tW production in the single-lepton channel in pp collisions at root s=13 TeV

A measurement of the cross section of the associated production of a single top quark and a W boson in final states with a muon or electron and jets in proton-proton collisions at root s = 13 TeV is presented. The data correspond to an integrated luminosity of 36 fb(-1) collected with the CMS detector at the CERN LHC in 2016. A boosted decision tree is used to separate the tW signal from the dominant t (t) over bar background, whilst the subleading W+jets and multijet backgrounds are constrained using data-based estimates. This result is the first observation of the tW process in final states containing a muon or electron and jets, with a significance exceeding 5 standard deviations. The cross section is determined to be 89 +/- 4 (stat) +/- 12 (syst) pb, consistent with the standard model.Peer reviewe

Measurements of Higgs boson production cross sections and couplings in the diphoton decay channel at root s=13 TeV

Measurements of Higgs boson production cross sections and couplings in events where the Higgs boson decays into a pair of photons are reported. Events are selected from a sample of proton-proton collisions at root s = 13TeV collected by the CMS detector at the LHC from 2016 to 2018, corresponding to an integrated luminosity of 137 fb(-1). Analysis categories enriched in Higgs boson events produced via gluon fusion, vector boson fusion, vector boson associated production, and production associated with top quarks are constructed. The total Higgs boson signal strength, relative to the standard model (SM) prediction, is measured to be 1.12 +/- 0.09. Other properties of the Higgs boson are measured, including SM signal strength modifiers, production cross sections, and its couplings to other particles. These include the most precise measurements of gluon fusion and vector boson fusion Higgs boson production in several different kinematic regions, the first measurement of Higgs boson production in association with a top quark pair in five regions of the Higgs boson transverse momentum, and an upper limit on the rate of Higgs boson production in association with a single top quark. All results are found to be in agreement with the SM expectations.Peer reviewe