Transition region of TEC enhancement phenomena during geomagnetically disturbed periods at mid-latitudes

Large-scale TEC perturbations/enhancements observed during the day sectors of major storm periods, 12-13 February 2000, 23 September 1999, 29 October 2003, and 21 November 2003, were studied using a high resolution GPS network over Japan. TEC enhancements described in the present study have large magnitudes (≥25×10<sup>16</sup> electrons/m<sup>2</sup>) compared to the quiet-time values and long periods (≥120 min). The sequential manner of development and the propagation of these perturbations show that they are initiated at the northern region and propagate towards the southern region of Japan, with velocities >350 m/s. On 12 February 2000, remarkably high values of TEC and background content are observed at the southern region, compared to the north, because of the poleward expansion of the equatorial anomaly crest, which is characterized by strong latitudinal gradients near 35° N (26° N geomagnetically). When the TEC enhancements, initiating at the north, propagate through the region 39-34° N (30-25° N geomagnetically), they undergo transitions characterized by a severe decrease in amplitude of TEC enhancements. This may be due to their interaction with the higher background content of the expanded anomaly crest. However, at the low-latitude region, below 34° N, an increase in TEC is manifested as an enhanced ionization pattern (EIP). This could be due to the prompt penetration of the eastward electric field, which is evident from high values of the southward Interplanetary Magnetic Field component (IMF <i>B<sub>z</sub></i>) and AE index. The TEC perturbations observed on the other storm days also exhibit similar transitions, characterized by a decreasing magnitude of the perturbation component, at the region around 39-34° N. In addition to this, on the other storm days, at the low-latitude region, below 34° N, an increase in TEC (EIP feature) also indicates the repeatability of the above scenario. It is found that, the latitude and time at which the decrease in magnitude of the perturbation component/amplitude of the TEC enhancement are matching with the latitude and time of the appearance of the high background content. In the present study, on 12 February 2000, the F-layer height increases at Wakkanai and Kokubunji, by exhibiting a typical dispersion feature of LSTID, or passage of an equatorward surge, which is matching with the time of occurrence of the propagating TEC perturbation component. Similarly, on 29 October 2003, the increase in F-layer heights by more than 150km at Wakkanai and 90 km at Kokubunji around 18:00 JST, indicates the role of the equatorward neutral wind. On that day, TEC perturbation observed at the northern region, after 18:30 JST, which propagates towards south, could be caused mainly by the equatorward neutral wind, leading to an F-layer height increase. These observations imply the role of the equatorward neutral wind, which increases the F-layer height, by lifting the ionization to the regions of lower loss during daytime, when production is still taking place, which, in turn, increases the TEC values. <P style="line-height: 20px;"> Large-scale traveling ionospheric disturbances (LSTIDs) are considered as ionospheric manifestations of the passage of Atmospheric Gravity Waves (AGWs) that are generated at the high latitude by energy input from the magnetosphere to the low-latitude ionosphere. This study shows that large-scale TEC perturbations observed here are produced at the northern region due to the combined effects of the equatorward neutral wind, the subsequent F-layer height increase, and LSTIDs. When these perturbation components propagate through the region, 39-34° N, they undergo transitions characterised by a decrease in magnitude. Also, at the low-latitude region, below 34° N, an increase in the TEC exhibits EIP feature, due to the prompt penetration of the eastward electric field

Initial wave packets and the various power-law decreases of scattered wave packets at long times

The long time behavior of scattered wave packets $\psi (x,t)$ from a finite-range potential is investigated, by assuming $\psi (x,t)$ to be initially located outside the potential. It is then shown that $\psi (x,t)$ can asymptotically decrease in the various power laws at long time, according to its initial characteristics at small momentum. As an application, we consider the square-barrier potential system and demonstrate that $\psi (x,t)$ exhibits the asymptotic behavior $t^{-3/2}$, while another behavior like $t^{-5/2}$ can also appear for another $\psi (x,t)$.Comment: 5 pages, 1 figur

Incidence of arthropods in dried fish products

Arthropods have been recorded from various types of insect infested dried fish products stored in the laboratory. They have been identified as Suidesia nesbetti Hughes (Acaridae) infesting dried anchovies and dried mussel, Dermestes ater Dermestidae coleoptera) attacking wet cured sardines and smoked catfish and Stegobium panicium infesting smoked catfish and dried mussel. Incidences of Stegobium panicium in dry fish products and Suidesia nesbetti in dried mussel has been recorded for the first time

Squilloides leptosquilla, a deepsea stomatopod landed at Kalamukku Fishing Harbour, Kochi

The mantis shrimp, Squilloides leptosquilla (Brooks, 1886) was obtained from deepsea trawl operations along with the deepsea shrimps, Plesionika spinipes, Heterocarpus gibbosus and Metapenaeopsis andamanensis from the Kalamukku Fishing Harbour during September, 2008

Proposal for an experiment to search for Randall-Sundrum type corrections to Newton's law of gravitation

String theory, as well as the string inspired brane-world models such as the Randall-Sundrum (RS) one, suggest a modification of Newton's law of gravitation at small distance scales. Search for modifications of standard gravity is an active field of research in this context. It is well known that short range corrections to gravity would violate the Newton-Birkhoff theorem. Based on calculations of RS type non-Newtonian forces for finite size spherical bodies, we propose a torsion balance based experiment to search for the effects of violation of this celebrated theorem valid in Newtonian gravity as well as the general theory of relativity. We explain the main principle behind the experiment and provide detailed calculations suggesting optimum values of the parameters of the experiment. The projected sensitivity is sufficient to probe the Randall-Sundrum parameter up to 10 microns.Comment: 4 pages and 5 figures, figures improved, minor clarifications and few references added, final version to appear in PRD (rapid communications

A comparison of intravenous lignocaine, intraperitoneal lignocaine, a combination of both on bowel recovery and pain relief in patients undergoing laparoscopic cholecystectomy

Background:Laparoscopic cholecystectomy (LC) is being increasingly performed as a day care surgery. Pain and lack of early bowel movements are common reasons preventing discharge on the same day.Methods: Study was conducted in a Government tertiary care institute in Kerala, South India. The effect of Intraperitoneal (IP), Intravenous (IV) and a combination of both on postoperative pain relief and bowel recovery was studied in 75 patients who were randomized in to 3 equal groups undergoing elective laparoscopic cholecystectomy. Group 1 IP lignocaine, Group 2 IV lignocaine and Group 3 combination of IP and IV lignocaine.Results: The time of bowel recovery and the pain scales at different time was compared using ANOVA test. Intergroup comparison of bowel recovery and pain scale was done using Bonferroni test. Pain score shows a statistically significant difference between Group 1 and Group 2 with a p value <0.001 and a statistically significant difference between Group1 and Group3 with a p value 0.126, but no statistical significance between Group 2 & Group3. The return of bowel activity was noted with perception of bowel movements and time for passage of flatus compared among the group, there was a statistically significant difference between the three groups.  Group 2 was found to be significantly better than the Group1 and Group3.Conclusions: Intravenous lignocaine is superior in bringing out early return of bowel activity when compared to all groups and Intravenous lignocaine is superior compared to intraperitoneal lignocaine in pain relief.

Importance of controlling diabetes early - The concept of metabolic memory, legacy effect and the case for early insulinisation

Most of the microvascular complications of diabetes are related to the degree and the length of exposure to hyperglycaemia. New data from the follow-up studies of the Diabetes Control and Complications Trial- the Epidemiology of Diabetes Intervention and Complications Study (DCCT- EDIC), and the United Kingdom Prospective Diabetes Study (UKPDS) emphasize the role of glycemic control early in the course of the disorder and its value in prevention of later complications. The phenomenon of ongoing beneficial effects on diabetic complications after a period of improved glycemic control even if followed by a return to usual (often poorer) metabolic control has been described as representing "metabolic memory" by the DCCT/EDIC investigators and as a "legacy effect" by the UKPDS investigators. This article reviews these concepts and explores the role of early use of insulin as a tool to achieve good glycemic control in type 2 diabetes

Free initial wave packets and the long-time behavior of the survival and nonescape probabilities

The behavior of both the survival S(t) and nonescape P(t) probabilities at long times for the one-dimensional free particle system is shown to be closely connected to that of the initial wave packet at small momentum. We prove that both S(t) and P(t) asymptotically exhibit the same power-law decrease at long times, when the initial wave packet in momentum representation behaves as O(1) or O(k) at small momentum. On the other hand, if the integer m becomes greater than 1, S(t) and P(t) decrease in different power-laws at long times.Comment: 4 pages, 3 figures, Title and organization changed, however the results not changed, To appear in Phys. Rev.