Manuscrits lul·lians de la Biblioteca de Catalunya. I

We have studied the correlates of cell death during stalk cell differentiation in Dictyostelium discoideum. Our main findings are four. (i) There is a gradual increase in the number of cells with exposed phosphatidyl serine residues, an indicator of membrane asymmetry loss and increased permeability. Only presumptive stalk cells show this change in membrane asymmetry. Cells also show an increase in cell membrane permeability under conditions of calcium-induced stalk cell differentiation in cell monolayers. (ii) There is a gradual fall in mitochondrial membrane potential during development, again restricted to the presumptive stalk cells. (iii) The fraction of cells showing caspase-3 activity increases as development proceeds and then declines in the terminally differentiated fruiting body. (iv) There is no internucleosomal cleavage of DNA, or DNA fragmentation, in D. discoideum nor is there any calcium- and magnesium-dependent endonucleolytic activity in nuclear extracts from various developmental stages. However, nuclear condensation and peripheralization does occur in stalk cells. Thus, cell death in D. discoideum shows some, but not all, features of apoptotic cell death as recognized in other multicellular systems. These findings argue against the emergence of a single mechanism of 'programmed cell death (PCD)' before multicellularity arose during evolution

CMFRI Marine Fisheries Policy Series No-4; Indian Marine Fisheries Code: Guidance on a Marine Fisheries Management Model for India

India’s marine fisheries are at a turning point; the rapid increase in yields witnessed during the first 60 years of independence has slowed down and the scope for increase in yields from new unexploited and underexploited fish stocks and grounds seems limited. The situation calls for urgent measures to sustain the production close to the target potential yield of 4.41 million tonnes. These measures would mean implementation of science based fisheries management and regulations. Although much has been accomplished by way of research and development in marine fisheries in India, the transformation and implementation of the outcome of these studies into effective management of marine fisheries resources of the country has been a shortcoming so far. The FAO brought out the Code of Conduct for Responsible Fisheries (FAO-CCRF) in 1995 to serve as a guidance for countries for a sound and effective management of fisheries resources. This FAO-CCRF has not been put into practice in India, althrough there are some compliances. Scientists of the CMFRI and CIFT, two of India’s major fisheries research institutes, have come together to develop a guidance on how the code can be put into practice in the country. Aptly named as Indian Marine Fisheries Code (IMFC), it is expected to give an impetus to bring about a sea change in the manner in which marine fisheries is managed in the country. The IMFC explains in detail each sub-article of the FAOCCRF and provides information on how the article can be implemented and by whom. The IMFC further proposes several new bodies which are necessary to place fisheries management in the country on an unassailable footing. It is expected that all fisheries management bodies in the country, both at central and state levels would find the IMFC as a useful guidance for the future

Doping effects in the coupled, two-leg spin ladder BiCu2PO6

We report preparation, x-ray diffraction, magnetic susceptibility chi(T) and heat capacity Cp(T) measurements on the undoped samples as also samples with Zn-doped (S = 0) at Cu site, Ni doped (S = 1) at Cu site, and Ca-doped (holes) at Bi site in the coupled two-leg spin ladder system BiCu2PO6. While, Zn shows complete solid solubility, Ni could be doped to about 20% and Ca to about 15%. Magnetization and heat capacity data in the undoped compound point towards the existence of frustration effects. In all the samples, the chi(T) at low temperature increases with doping content. The Zn-induced susceptibility is smaller than that due to effective S=1/2 moments possibly due to frustrating next-nearest-neighbor interactions along the leg. For Zn content x > 0.01, chi(T) deviates from the Curie-law at low temperatures. The magnetic specific heat data Cm(T) for the Zn-doped samples show weak anomalies at low temperature in agreement with chi(T) behavior. The anomalies are suggestive of spin freezing at low-T. In contrast, prominent effects are observed in chi(T) and Cm(T) on Ni-doped samples. The zero-field-cooled (ZFC) and field-cooled (FC) chi(T) data are different from each other at low temperature unlike that for Zn doped samples, clearly indicating a transition to a spin-glass like phase. No anomalies were found in Ca- or Pb-doped samples.Comment: 16 pages, 9 figures, Submitted to J. Phy. Cond. Matte

Marine Fish Calendar. 2. Visakhapatnam

Gear wise landing details of the fish species in the important families (e.g. Clupeidae,Scombridae, Sciaenidae, etc.), groups (e.g. sardines,mackerel, croakers, etc.) in the Vishakapatnam landing centre during 1981-1986 was provided in the article

Optical variability properties of high luminosity AGN classes

We present the results of a comparative study of the intra-night optical variability (INOV) characteristics of radio-loud and radio-quiet quasars, which involves a systematic intra-night optical monitoring of seven sets of high luminosity AGNs covering the redshift range {\it z} $\simeq 0.2$ to {\it z} $\simeq 2.2$. The sample, matched in the optical luminosity -- redshift (M$_B$ -- z) plane, consists of seven radio-quiet quasars (RQQs), eight radio lobe-dominated quasars (LDQs), six radio core-dominated quasars (CDQs) and five BL Lac objects (BLs). Systematic CCD observations, aided by a careful data analysis procedure, have allowed us to detect INOV with amplitudes as low as 1%. Present observations cover a total of 113 nights (720 hours) with only a single quasar monitored as continuously as possible on a night. Considering cases of only unambiguous detections of INOV we have estimated duty cycles (DCs) of 17%, 12%, 20% and 72% respectively for RQQs, LDQs, CDQs, and BLs. The low amplitude and low DC of INOV shown by RQQs compared to BLs can be understood in terms of their having optical synchrotron jets which are modestly misdirected from us. From our fairly extensive dataset, no unambiguous general trend of a correlation between the INOV amplitude and the apparent optical brightness of the quasar is noticed.Comment: 36 pages, 14 Figures, due to large size Fig. 5,6,11 and 12 are not included. Intersted people contact to [email protected]. Submitted to Journal of Astrophysics and Astronom

Anomalous field-dependent specific heat in charge-ordered Pr1−x_{1-x}Cax_xMnO3_3 and La0.5_{0.5}Ca0.5_{0.5}MnO3_3

We report low temperature specific heat measurements of Pr$_{1-x}$Ca$_{x}$MnO$_{3}$ ($0.3\leq x \leq 0.5$) and La$_{0.5}$Ca$_{0.5}$MnO$_{3}$ with and without applied magnetic field. An excess specific heat, $C^{\prime}(T)$, of non-magnetic origin associated with charge ordering is found for all the samples. A magnetic field sufficient to induce the transition from the charge-ordered state to the ferromagnetic metallic state does not completely remove the $C^{\prime}$ contribution. This suggests that the charge ordering is not completely destroyed by a "melting" magnetic field. In addition, the specific heat of the Pr$_{1-x}$Ca$_{x}$MnO$_{3}$ compounds exhibit a large contribution linear in temperature ($\gamma T$) originating from magnetic and charge disorder.Comment: submitted to PRL 5 pages, 3 figures include

Sodium-coupled Monocarboxylate Transporters in Normal Tissues and in Cancer

SLC5A8 and SLC5A12 are sodium-coupled monocarboxylate transporters (SMCTs), the former being a high-affinity type and the latter a low-affinity type. Both transport a variety of monocarboxylates in a Na+-coupled manner. They are expressed in the gastrointestinal tract, kidney, thyroid, brain, and retina. SLC5A8 is localized to the apical membrane of epithelial cells lining the intestinal tract and proximal tubule. In the brain and retina, its expression is restricted to neurons and the retinal pigment epithelium. The physiologic functions of SLC5A8 include absorption of short-chain fatty acids in the colon and small intestine, reabsorption of lactate and pyruvate in the kidney, and cellular uptake of lactate and ketone bodies in neurons. It also transports the B-complex vitamin nicotinate. SLC5A12 is also localized to the apical membrane of epithelial cells lining the intestinal tract and proximal tubule. In the brain and retina, its expression is restricted to astrocytes and Müller cells. SLC5A8 also functions as a tumor suppressor; its expression is silenced in tumors of colon, thyroid, stomach, kidney, and brain. The tumor-suppressive function is related to its ability to mediate concentrative uptake of butyrate, propionate, and pyruvate, all of which are inhibitors of histone deacetylases. SLC5A8 can also transport a variety of pharmacologically relevant monocarboxylates, including salicylates, benzoate, and γ-hydroxybutyrate. Non-steroidal anti-inflammatory drugs such as ibuprofen, ketoprofen, and fenoprofen, also interact with SLC5A8. These drugs are not transportable substrates for SLC5A8, but instead function as blockers of the transporter. Relatively less is known on the role of SLC5A12 in drug transport