The geographical patterns of tree species richness in forest communities have been studied widely, but little is known about the geographical variation of the estimated species richness and minimum areas using species-area curves. A differential technique based on the species-area relationships (SAR) was developed for estimating the minimum area (Amin) capturing 60- 80% of the species in each plot, which is an important characteristic of a forest community. The relationship between estimated species richness (ESR) from the SAR and the corresponding minimum area is described by the linear model ESR = 0.0051×Amin (R2 = 0.98, p < 0.0001). Both the ESR and the minimum area exhibit similar geographical variations with a significant increase along altitudinal and a decrease along latitudinal gradients. The spatial variations of the ESR were partitioned into three geographical components and their combined effects. Altitude accounted for 40% and 45% of the total variation in the ESR and the minimum area, respectively. While latitude accounted for 69% and 61% of the total variation in the ESR and the minimum area, respectively. Thus, latitude is the main determinant which influences the geographical variation of the ESR. As far as we know, this study presents the first report of the geographical patterns of the minimum area in temperate forests.
Aerva lanata collected during summer, monsoon and winter were subjected to similar extraction conditions as well as sample application conditions on precoated silica 60F254 TLC plates. The plates were developed in ethyl acetate-toluene (7:3 v/v) in order to study the seasonal variation in HPTLC fingerprints. A similar procedure was also followed for the plant samples collected from three different states of India, in order to study the geographical variation. p-Hydroxybenzoic acid, used as reference standard for comparison with each sample, was observed in samples collected in all three seasons but in different concentrations. The compound was also observed in samples collected from Gujarat and Maharashtra, but was found to be absent in the sample from Kerala. The sample from Kerala showed a different compound at RF 0.74, having a λmax of 280 nm. This compound exhibited a spectrum very different from that of p-hydroxybenzoic acid having a λmax of 252 nm, which separates out at RF 0.73 on the plate. The proposed method was validated according to ICH guidelines in terms of linearity, accuracy and specificity, intra-day and inter-day precision, repeatability of measurement of peak area, repeatability of sample application and specificity. The calibration graph was found to be linear over a range of concentration of 25.0–175.0 ng, with a regression coefficient of 0.9986. Determination of accuracy by standard addition method at three different concentration levels returned a mean recovery value of 97.24 ± 7.36. Intra-day and inter-day precision values were found to be less than 2%. The relative standard deviations (RSDs) of repeatability of sample application and measurement of area were found to be 1.24% and 0.93%, respectively.
analysing geographicvariations in knowledge exchange networks, we can detect regional differences in accessibility to both local and extra-local knowledge resources and find how second tier regions may become successful in innovation.
As an emerging
This paper analyses the changing geographic balance in China’s international co-publications in general and in three molecular
life science subfields in particular. No support is found for the expectation that intensive, designated institutional support
for research collaboration in the form of joint laboratories has a positive impact on the number of co-publications at the
systemic level. The size of partner research systems, and since the turn of the century the relative size of overseas Chinese
scientific communities in various partner countries do help to explain the observed geographic variations in the share of
China’s international co-publications. The paper concludes by discussing some of the potential factors underlying the perceived
change in the dynamics of international co-publication behavior of mainland Chinese scientists since the turn of the century.
The ultimate purpose of all studies on environmental contamination is to protect human life; as a consequence the knowledge
of the trace element pathways from environment to man is of paramount importance because it allows the assessment of a clear
relationship between any environmental contamination and its effects on man. To this extent two different kinds of environmental
studies will be described in this paper: (a) Studies of the geographic variations on the whole national territory of the natural
levels of trace elements in water, food and some human tissues. (b) Studies of selected areas where a critical population
group is exposed to abnormal levels of some trace elements. The main trace elements considered are: Co, Cr, Cs, Fe, Hg, Ni,
Rb, Sb, Sc, Se and Zn; all the measurements were performed by means of non-destructive neutron activation analysis.
Fourteen samples of fresh curry leaves (Murraya Koenigii) were collected from 13 states of India and analyzed for 6 minor (Ca, Cl, K, Mg, Na and P) and 14 trace (Br, Ce, Co, Cr, Cs,
Fe, Hg, Mn, Rb, Sb, Sc, Se Th and Zn) elements by 2-minute irradiation in a reactor followed by high resolution g-ray spectrometry.
Peach Leaves (SRM-1547) and Mixed Polish Herbs (MPH-2) were used as comparator standards. Phosphorus was determined by counting
the b-activity from 32P using an end-window GM counter. Most elements were found to vary in a wide range depending on their origin of location,
e.g., Na (104-455 mg/g), K (10.3-30.3 mg/g), Ca (9.44-28.3 mg/g), Mg (1.14-7.19 mg/g), P (0.43-1.69 mg/g), Mn (24.8-63.0 mg/g),
Fe (72.5-195 mg/g), Se (40.1-131 ng/g) and Zn (7.90-70.5 mg/g). Variation in the elemental concentrations of the same species
of different origin may be attributed to ecological and geographical variations. Further, column and thin layer chromatography
were used for separating three organic constituents from the ethanolic extract; 3-methylthiopropanenitrile; 1,2-benzenedicarboxylic
acid, mono (2-ethylhexyl ester) and 1-penten-3-ol and characterized by IR and GC-MS. Inorganic elements may be present as
complexes with the organic compounds.
Összefoglaló. A Helicobacter pylori továbbra is a
világ legelterjedtebb fertőzése: prevalenciája a fejlődő országokban 70–80%, a
fejlett országokban csökkenő tendenciát mutat. A dél-magyarországi véradókban a
prevalencia 32%-ra csökkent. A migráció a befogadó ország számára a fertőzés
fokozott kockázatával jár. A szövettani diagnózisban az immunhisztokémiai
vizsgálat pontosabb a hagyományos Giemsa-festésnél. A mesterséges intelligencia
érzékenysége a hagyományos endoszkópiáéval összehasonlítva 87%, pontossága 86%.
Az újgenerációs szekvenálással lehetséges egy biopsziás mintából több
antibiotikumérzékenység meghatározása. A Helicobacter pylori
kezelésének európai regisztere kimutatta, hogy 2013 és 2018 között a bizmutalapú
négyes vagy a 14 napos egyidejű négyes kezelések hatásosabbak, mint a
hagyományos hármas kezelés, de elterjedésük igen lassú folyamat, jelentős
földrajzi különbségekkel. Az új típusú koronavírus (SARS-CoV-2) felléphet
Helicobacter pylori fertőzésben is, egymás kóros hatását
felerősítve. A diagnosztikai módszerek korlátozottak. Protonpumpagátlók szedése
növeli a COVID–19-fertőzés kockázatát és annak súlyos kimenetelét. Előzetesen
ismert peptikus fekély, vérzés, illetve antikoguláns kezelés előtt az eradikáció
a vírusos fertőzés lezajlása után indokolt. A probiotikumoknak az eradikációra
gyakorolt hatásáról 20, közepes minőségű metaanalízis született, így a
konszenzusokban foglalt álláspontok sem egyértelműek: a jövőben ezt tisztázni
kell. Orv Hetil. 2021; 162(32): 1275–1282.
Summary.Helicobacter pylori is still the most widespread infection in
the world: its overall prevalence is 70–80% in developing regions, but
fortunately it is decreasing in the Western world. The prevalence in blood
donors from South-Eastern Hungary decreased from 63% in the 1990’s to 32% in
2019. Migration constitutes an increased risk of infection for the destination
countries. Immunohistochemistry has proven to be more accurate in histological
diagnosis than the conventional Giemsa stain. The sensitivity and accuracy of
artificial intelligence as compared to videoendoscopy were 87% and 86%,
respectively. The European Register on the management of Helicobacter
pylori infection revealed that concomitant quadruple and 14-day
bismuth-based therapies are more efficient than triple combinations, although
their incorporation in practice is a long-lasting process, with large
geographical variations. The novel type of coronavirus (SARS-CoV-2) can also
occur in Helicobacter pylori-infected patients, mutually
enhancing their pathogenetic effects. Diagnostic possibilities are limited in
this setting. The use of proton pump inhibitors increases the risk of viral
infection and the severity of the disease. Eradication treatment seems justified
in patients with previously known peptic ulcers or gastrointestinal bleeding, or
before starting anticoagulant treatment, but must be postponed after resolution
of viral infection. The effect of probiotics on eradication was addressed by 20,
medium-to-low quality meta-analyses and so, the recommendations of the
guidelines are equivocal, which must be clarified in the future with higher
quality studies. Orv Hetil. 2021; 162(32): 1275–1282.
geographicalvariation of growth habit and Vrn genotype. Plant Breed. , 120 , 107-114.
Adaptation and ecological differentiation in wheat with special reference to geographicalvariation of growth habit and Vrn genotype