bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Tillage Systems on the Productivity of Wheat Varieties in the Conditions of Balkh Afghanistan
Authors: Ansari Mohammad Akbar , Osmani Khuwaja Safiullah , Payenda Poya , Yonusi Mohammad Mobin 
Published: March 2023

In Afghanistan, the greatest challenges in agriculture system are major soil erosion, high soil moisture loss, and farming of the same crop every year leads to drop in fertility level of the soil. Conservation Agriculture defined by three principles namely minimum soil disturbance, crop rotation and permanent soil cover. A field experiment was conducted during winter and summer season of 2018 at research farm of Dehdadi, Balkh, Afghanistan. The experiment was laid out in a split plot design, comprising ten treatment combinations. The main factor was conservation agriculture and conventional agriculture with sub factor by five varieties of wheat (Moqawium, Baghlan, Chunt, Darlaman and local).The main objective of this study is to compare and determine the performance of new wheat varieties under conservation and conventional agriculture, for improving and identifying it’s effect on wheat yield and wheat varieties under conservation agriculture.
The result indicated that different soil conservation practice could cause significant changes in term of wheat growth and yield attributes like bundle weight and yield of wheat and among wheat varieties Chunte variety significantly difference on number of tillers, bundle weight, straw yield, yield and thousand wheat kernel as compare to local wheat variety. In short time there was not any difference in soil chemical and physical of soil in term of pH, OC, N, P and K, but in long term there will be minor changes occur, so we do recommend conserving to improve the soil fertility and cultivate the chunte variety for more yield.
Modeling of Growth, Lactate Consumption, and Volatile Fatty Acid Production by Megasphaera elsdenii Cultivated in Minimal and Complex Media
Authors: Soto‐Cruz Oscar , Favela‐Torres Ernesto , Saucedo‐Castañeda Gerardo 
Published: July 2002

AbstractUse of the Pirt and Luedeking–Piret equations permits the determination of the effect of medium composition on the metabolic patterns of Megasphaera elsdenii grown in minimal and complex media with lactate as the major carbon source. To establish the significance of the parameters involved in the Pirt and Luedeking–Piret equations, a quantitative statistical criterion was proposed. In the complex medium, lactate was completely used for growth and product formation, whereas in the minimal medium a fraction of the energy obtained from lactate was used for maintenance purposes. Modeling of VFA production by the Luedeking–Piret equation showed that, independent of the type of medium, acetate and propionate are growth‐associated products, while butyrate and valerate are only partially growth‐associated. The growth‐associated products are related to energy‐yielding metabolism and the non‐growth‐associated products are related to the consumption of reducing equivalents.
Growth Kinetics, Nutrient Uptake, and Expression of the Alcaligenes eutrophus Poly(β‐hydroxybutyrate) Synthesis Pathway in Transgenic Maize Cell Suspension Cultures
Authors: Hahn J. J. , Eschenlauer Arthur C. , Narrol Matt H. , Somers David A. , Srienc Friedrich 
Published: July 2002

AbstractTransgenic suspension cultures of Black Mexican Sweet maize (Zea mays L.) expressing the Alcaligenes eutrophus genes encoding enzymes of the pathway for biosynthesis of the biodegradable polymer poly(β‐hydroxybutyrate) (PHB) were established as a tool for investigating metabolic regulation of the PHB pathway in plant cells. Cultures were grown in a 2 L modified mammalian cell bioreactor and in shake flasks. Biomass doubling times for transgenic bioreactor cultures (3.42 ± 0.76 days) were significantly higher than those for untransformed cultures (2.01 ± 0.33 days) . Transgenic expression of the bacterial enzymes β‐ketothiolase (0.140 units/mg protein) and acetoacetyl‐CoA reductase (0.636 units/mg protein) was detected by enzyme assays and immunoblots. However, over the first 2 years of cultivation, reductase activity decreased to 0.120 units/mg protein. Furthermore, the PHB synthase gene, although initially present, was not detectable after 1.5 years of cultivation in suspension culture. These facts suggest that transgenic expression of PHB pathway genes in plant cells may not be stable. A hydroxybutyrate derivative was detected via gas chromatography even after 4 years of cultivation. Although the method used to prepare samples for gas chromatography cannot directly distinguish among PHB polymer, hydroxybutyryl‐CoA (HB‐CoA), and hydroxybutyric acid, solvent washing experiments indicated that most or all of the signal was non‐polymeric, presumably HB‐CoA. The synthesis of HB‐CoA appeared to be linked to substrate growth limitation, with HB‐CoA accumulation increasing dramatically and cell growth ceasing upon depletion of ammonium. This suggests that the PHB synthesis pathway in plants is subject to regulatory mechanisms similar to those in prokaryotic cells.
Increased incidence of Acanthamoeba keratitis associated with contact lens wear: the need to prevent this waterborne infection
Authors: Seal D. , Hay J. , Kirkness O. M. ,   West of Scotland Keratitis Study Group
Published: July 2002

The incidence of Acanthamoeba keratitis has been assessed in the 1995 West of Scotland Keratitis Study. All patients with microbial keratitis in the 3 million population were reported to us prospectively by optometrists, ophthalmologists and microbiologists. Contact lens (CL) wearing patients completed detailed questionnaires; 50 healthy CL wearers were visited at home as controls and similarly investigated. Additionally all 340 optician practices were polled for their annual turnover of CL types and disinfectant solutions. Acanthamoeba keratitis occurred with an incidence of 1/10000 CL wearers based on this large, reliable community study of 164 000 CL wearers. This is 25 times more frequent than the previous American estimate (i.e. 1:250 000). The relationship to CL material type, ineffective cold chemicals solutions and hygiene compliance is complex, but is directly related to use of contaminated tap water as part of CL care, this vehicle being the source of the amoebae.These findings are of considerable concern. They suggest that many new cases of painful, distressing and potentially blinding infection will be seen in Asia as CL wear becomes more widely available. Local expertise for recognition of Acanthamoeba keratitis will be required plus treatment with a combination of 0.02% chlorhexidine and 0.1% propamidine. Tap water must be avoided in CL care, and rigorous attention paid to CL hygiene.
Improved photovoltaic properties for Au/AlPcCl/n-Si solar cells with morphology-controlled AlPcCl deposition
Authors: Yanagi Hisao , Kataura Hidenori , Ueda Yasukiyo 
Published: July 2002

Photovoltaic solar cells were constructed by successive vacuum deposition of chloroaluminum phthalocyanine (AlPcCl) and Au on a single-crystal n-Si wafer. By controlling the thickness and morphology of the AlPcCl deposits in the Au/AlPcCl/n-Si cells, an improved photovoltaic efficiency was obtained as compared to the Au/n-Si Schottky-type cell. The cell with a homogeneous, ultrathin (10 nm thickness) AlPcCl film, which was prepared by deposition on an n-Si substrate kept at −20 °C, exhibited a high photovoltage (Voc=0.45 V) and strongly sensitized photocurrents in the Q-band absorption region (600–800 nm) of AlPcCl chromophore. This improved photoresponse was attributed to a space-charge layer generated inside the AlPcCl film, where the intervening AlPcCl layer prevented the n-Si surface from forming surface states because of noncontact with the Au top electrode. When discontinuous island crystallites of AlPcCl were formed on the n-Si surface kept at 200 °C, the Au/AlPcCl/n-Si cell also exhibited an improved efficiency with a high photovoltage (Voc=0.42 V).
The discontinuous AlPcCl coverage, providing both the Au/n-Si Schottky contact and AlPcCl/n-Si heterojunction, modulated a diffusion potential at the space-charge region to give rise to a steep barrier gradient at the edges of the AlPcCl island. Its high photovoltaic response was attributed to an efficient charge-carrier separation from excitons that were generated on the uncoated n-Si area and diffused at the AlPcCl-island edge.
Photoluminescence and Auger spectroscopy of porous Si: Solvent, reactive ion etching, annealing, and substrate boron level effects
Authors: Shinar R. , Robinson D. S. , Partee J. , Lane P. A. , Shinar J. 
Published: July 2002

The photoluminescence (PL) at λ≤850 nm of boron-doped porous Si films anodically etched, passively etched, annealed, and reactive ion etched (RIE) under systematically varied conditions is described and discussed. As previously observed, the PL yield η of films etched from 7 to 20 Ω cm wafers in HF/H2O/C2H5OH solutions rapidly degraded during 40 mW illumination in air at 488 nm. In addition, it was totally quenched by O2 annealing or RIE but not by H2 RIE. However, the yield of films etched in HF/H2O only decreased by less than 10% following similar illumination for 7 h, and O2 annealing or RIE reduced it by 0%–50% only. The instability under illumination, the effects of oxygen annealing and RIE, Auger line shape measurements, and surface charge buildup during Auger analysis are consistent with a significantly higher density of weak Si—Si bonds in films etched in ethanol-containing solutions. These bonds are apparently broken by photoinduced oxidation, oxygen annealing, or O2 RIE, but the oxygen does not efficiently passivate the newly generated dangling bonds. While the peak emission wavelength λmax of the films etched from these wafers shifted with annealing and etching conditions, it invariably peaked in the ∼7600–8600 Å range; η reached ∼1.7%. H2 RIE had no effect on η, but λmax was blueshifted. This behavior is attributed to similar breaking of weak Si—Si bonds followed by efficient passivation of the newly generated dangling bonds.
The blueshift results from the higher H/Si ratio; the invariant yield is believed to be limited by the density of dangling bonds at the SiOxHy/Si interface which is apparently unaffected by the treatments. It is therefore believed that the PL is at least partially due to SiHx or SiOxHy complexes on the crystallite and column surfaces, which are similar to those found at the surface of some H-rich a-Si:H. Size effects, however, cannot be ruled out. In contrast to films etched from 7 to 20 Ω cm wafers, λmax of those prepared from 1 to 2 Ω cm substrates was consistently ∼7000 Å after a brief exposure to air. While η exhibited a complex dependence on the O2 RIE power, λmax was unchanged by either O2 or H2 plasmas. The emission from heavily doped ∼0.02 Ω cm films was usually undetectable. However, H2 RIE resulted in observable PL.
Infrared photofragmentation spectra of size-selected SF6⋅Ar+n cluster ions
Authors: Winkel J. F. , Woodward C. A. , Jones A. B. , Stace A. J. 
Published: July 2002

Results are presented of a detailed experimental study of the infrared photofragmentation patterns of size-selected SF6⋅Ar+n cluster ions for n in the range 3 to 70. Line-tuneable CO2 and N2O lasers have been used to excited the ν3 vibrational mode of the SF6 molecule which is followed by the loss of one and two argon atoms as the principal fragmentation routes. Which of the two processes is dominant depends quite strongly on the size of the cluster ion concerned, with very pronounced fluctuations in the relative intensities of photofragments being observed for cluster ions in the range SF6⋅Ar+3 to SF6⋅Ar+25. Only for SF6⋅Ar+3 is the fragmentation pattern markedly different from that found for the other ions; an observation that supports an earlier conclusion regarding the relative ionisation energies of the two constituents [Stace et al. J. Phys. Chem. 97, 11363 (1993)]. A summation of fragment ion intensities as a function of laser wavelength is used to determine infrared absorption profiles and these have been recorded for individual clusters containing up to 70 argon atoms. Clusters containing fewer than 40 argon atoms appear to form single structures, with both the absorption profile shapes and selected hole-burning experiments suggesting that the number of isomers is small.
The presence of isomers only appears to become significant when the clusters contain more than 40 argon atoms. The observation of site splittings for the triply degenerate ν3 vibrational mode of SF6, together with the comparatively narrow linewidths seen for clusters containing between 15 and 40 rare gas atoms, indicates the presence of ordered structures. Such a conclusion implies that the clusters are solidlike rather than liquidlike. Overall, the results demonstrate that there is a clear correlation between those criteria previously used to identify the presence of stable cluster ion structures, i.e., mass spectra and unimolecular fragmentation patterns, and the corresponding infrared fragmentation patterns and absorption profiles. Of the ions studied, SF6⋅Ar+21 stands out as being particularly stable and worthy of future theoretical attention.
On tractability of path integration
Authors: Wasilkowski Grzegorz W. , Woźniakowski Henryk 
Published: July 2002

Many applications require approximate values of path integrals. A typical approach is to approximate the path integral by a high dimensional integral and apply a Monte Carlo (randomized) algorithm. However, Monte Carlo algorithm requires roughly ε−2 integrand evaluations to provide an ε approximation. Moreover, the error bound of ε is guaranteed only in a stochastic sense. Do we really need to use randomized algorithms for path integrals? Perhaps, we can find a deterministic algorithm that is more effective even in the worst case setting. To answer this question, we study the worst case complexity of path integration, which, roughly speaking, is defined as the minimal number of the integrand evaluations needed to compute an approximation with error at most ε. We consider path integration with respect to a Gaussian measure, and for various classes of integrands. Tractability of path integration means that the complexity depends polynomially on 1/ε. We show that for the class of r times Frechet differentiable integrands, tractability of path integration holds iff the covariance operator of the Gaussian measure has finite rank. Hence, if the Gaussian measure is supported on an infinite dimensional space then path integration is intractable.
In this case, there exists no effective deterministic algorithm, and the use of randomized algorithms is justified. In fact, for this class of integrands, the classical Monte Carlo algorithm is (almost) optimal and the complexity in the randomized setting is proportional to ε−2. On the other hand, for a particular class of entire integrands, the worst case complexity of path integration is at most of order ε−p with p depending on the Gaussian measure. Hence, path integration is now tractable. Furthermore, for any Gaussian measure, the exponent p is less than or equal to 2. For the Wiener measure, p=2/3. For this class, we provide effective deterministic algorithms which solve the path integration problem with (worst case) cost that is usually much less than the (randomized) cost of the classical Monte Carlo algorithm.
Joint European Torus results with both fast and lower-hybrid wave consequences for future devices
Authors: Jacquinot J. , Bures M. ,   the JET Team
Published: July 2002

Heating and current drive studies were performed during the JET [Phys Fluids B 3, 2209 (1991)] 1990/91 operation using two large systems capable of generating either fast waves in the ion cyclotron range of frequencies (ICRF) or slow waves at a frequency above the lower-hybrid resonance (LH). The maximum wave power coupled to the torus reached 22 MW for ICRH and 2.4 MW for LH. The results obtained in plasma heating experiments qualify ICRH as a prime candidate for heating reactor grade plasmas. A centrally localized deposition profile in the cyclotron damping regime was demonstrated in a wide range of plasma density resulting in (i) record value nd τE Ti0 ≂ 7.8 × 1020 m−3 sec keV in ‘‘thermal’’ conditions Ti = Te ≂ 11 keV at high central densities generated by pellet injection; (ii) large normalized confinement 2.5 ≤ τE/τGoldston≤4. The large values of τE/τGoldston are reached in H-mode discharges (I≤1.5 MA) with large bootstrap current fraction IBS/I ≤ 0.7 ± 0.2; (iii) the highest to date D–3He fusion power (140 kW) generated with 10–14 MW of ICRH in the L-mode regime at the 3He cyclotron frequency. All specific impurity generations have been reduced to negligible levels by proper antenna design and the generic difficulty of wave–plasma coupling has been greatly reduced using feedback loops controlling in real time the antenna circuits and the plasma position.
Current drive efficiencies γ=ICD〈ne〉R/P ≂ 0.4 × 1020 m−2 A/W have been reached in 1.5 MA L-mode plasma with zero loop voltage by combining LHCD and ICRH. Fast electrons are driven by LHCD alone to tail temperatures of up to 70 keV. The fast electron density is peaked in the plasma center at lower densities (ne0 ≤ 2.6 × 1019 m−3) and high field (Bφ ∼ 3.1 T). In these conditions, the fast electrons are further accelerated (even at zero loop voltage) to tail temperatures above 150 keV by heating the plasma with ICRF in monopole phasing. Direct electron damping of the fast wave on the fast electrons created by LH appears to be the driving mechanism of this synergism which produces fast wave current drive even without phasing the ICRH antennas. Finally, the first results obtained in the minority current drive regime are reported. The sawtooth instability is considerably modified when the resonance is located near the q=1 resonance. The effect is reversed from stabilization to destabilization when the phase of the ICRH antennas is reversed from +90° to −90°.
Lexical diversity and productivity in Cantonese‐speaking children with specific language impairment
Authors: Stokes Stephanie F. , Fletcher Paul 
Published: July 2002

AbstractRecent studies of lexical diversity in English‐speaking children with specific language impairment (ESLI) have produced conflicting results. Differences between SLI and age‐matched (AM) groups on verb types, and overall types have been reported, as have differences between SLI and language‐matched (LM) groups on verb types and/or verb tokens, and noun types and noun tokens. At the same time there have been other claims that there is no difference between SLI and LM groups in terms of lexical diversity. This comparison of the lexical diversity of Cantonese‐speaking children with SLI (CSLI) and their language‐matched peers controlled the length of the samples and the number of tokens as the basis for comparison. There was no difference between the groups in use of verb tokens or types, but there were significant differences in noun tokens and types and ‘other’ open class tokens and types. Although there was no difference between the groups in the use of a specific grammatical marker (aspect markers), the way in which the CSLI children deployed these markers was severely restricted in comparison with their LM peers. A limited capacity model of language production is invoked to explain the findings.
Remarkable Conservation of Translation Initiation Factors: IF1/eIF1A and IF2/eIF5B are Universally Distributed Phylogenetic Markers
Authors: Sørensen Hans Peter , Hedegaard Jakob , Sperling‐Petersen Hans Uffe , Mortensen Kim Kusk 
Published: July 2002

AbstractInitiation of protein biosynthesis is an essential process occurring in cells throughout the three phylogenetic domains, Bacteria, Archaea, and Eucarya. IF1/eIF1A and IF2/eIF5B, two conserved translation initiation factors are involved in this important step of protein biosynthesis. The essentiality, universal distribution, conservation, and interspecies functional homology of both factors are a unique combination of properties ideal for molecular phylogenetic studies as demonstrated by the extensively compared SSU rRNAs. Here, we assess the use of IF1/eIF1A and IF2/eIF5B in universal and partial phylogenetic studies by comparison of sequence information from species within all three phylogenetic domains and among closely related strains of Haemophilus parainfluenzae . We conclude that the amino acid sequence of IF1/eIF1A‐IF2/eIF5B is a universal phylogenetic marker and that the nucleotide sequence of the IF2/eIF5B G‐domain is more credible than SSU rRNA for the construction of partial phylogenies among closely related species and strains. Because of these two application levels, IF1/eIF1AIF2/eIF5B is a phylogenetic “dual level” marker.
The Role of Dynamin and Its Binding Partners in Coated Pit Invagination and Scission
Authors: Hill Elaine , van der Kaay Jeroen , Downes C. Peter , Smythe Elizabeth 
Published: July 2002

Plasma membrane clathrin-coated vesicles form after the directed assembly of clathrin and the adaptor complex, AP2, from the cytosol onto the membrane. In addition to these structural components, several other proteins have been implicated in clathrin-coated vesicle formation. These include the large molecular weight GTPase, dynamin, and several Src homology 3 (SH3) domain–containing proteins which bind to dynamin via interactions with its COOH-terminal proline/arginine-rich domain (PRD). To understand the mechanism of coated vesicle formation, it is essential to determine the hierarchy by which individual components are targeted to and act in coated pit assembly, invagination, and scission.
To address the role of dynamin and its binding partners in the early stages of endocytosis, we have used well-established in vitro assays for the late stages of coated pit invagination and coated vesicle scission. Dynamin has previously been shown to have a role in scission of coated vesicles. We show that dynamin is also required for the late stages of invagination of clathrin-coated pits. Furthermore, dynamin must bind and hydrolyze GTP for its role in sequestering ligand into deeply invaginated coated pits.
We also demonstrate that the SH3 domain of endophilin, which binds both synaptojanin and dynamin, inhibits both late stages of invagination and also scission in vitro. This inhibition results from a reduction in phosphoinositide 4,5-bisphosphate levels which causes dissociation of AP2, clathrin, and dynamin from the plasma membrane. The dramatic effects of the SH3 domain of endophilin led us to propose a model for the temporal order of addition of endophilin and its binding partner synaptojanin in the coated vesicle cycle.
Sums of squares of regular functions on real algebraic varieties
Authors: Scheiderer Claus 
Published: July 2002

Let

V
V

be an affine algebraic variety over

R

\mathbb {R}

(or any other real closed field

R
R

). We ask when it is true that every positive semidefinite (psd) polynomial function on

V
V

is a sum of squares (sos). We show that for

dim
⁡
V
≥
3

\dim V\ge 3

the answer is always negative if

V
V

has a real point. Also, if

V
V

is a smooth non-rational curve all of whose points at infinity are real, the answer is again negative. The same holds if

V
V

is a smooth surface with only real divisors at infinity. The “compact” case is harder. We completely settle the case of smooth curves of genus

≤
1

\le 1

: If such a curve has a complex point at infinity, then every psd function is sos, provided the field

R
R

is archimedean. If

R
R

is not archimedean, there are counter-examples of genus

1
1

.