PERIOD Research Articles

Altered CRYPTOCHROME Expression Profile is Correlated with Reduced Circadian Clock Plasticity in the yellow white, Drosophila melanogaster

The circadian clock that regulates behavior and physiology of animals is synchronized to the natural, 24 hour, light-dark cycle primarily by light. In Drosophila melanogaster, light is transduced to the clock neurons via the external photoreceptors in addition to the blue-light photopigment, CRYPTOCHROME (CRY), which plays a special role in clock phase resetting. Previous studies showed that the y w mutation in D. melanogaster is correlated with altered locomotor and molecular circadian rhythms, probably due to their disturbed eye pigmentation and sensitivity, and neurotransmitter physiology. This study investigates the relationship between this mutation and the CRY expression profile as a primary player in the photic entrainment pathway. Results revealed that CRY levels was most of the time higher in y w mutants compared to the wild-type CS fruit flies in all clock neuronal clusters expressing CRY. The reduced and delayed degradation of CRY indicates week photoreception by the mutants and provides a possible explanation for the delayed PERIOD (PER) and suppressed Pigment-Dispersing Factor (PDF) signaling detected previously. It could also explain the delayed morning and advanced evening locomotor activity peaks of these y w mutants. The results also showed a higher level of variation in CRY staining between individual neurons within each cluster, probably due to reduced PDF signaling which is known to internally synchronize clock neurons. It could be concluded that, the mutations affecting the photic entrainment pathway to the circadian clock, like the y w mutation, would probably have widespread effects on the circadian clock machinery and the overt rhythms under its regulation

Vaccinia-related kinase 3 (VRK3) sets the circadian period and amplitude by affecting the subcellular localization of clock proteins in mammalian cells

In the eukaryotic circadian clock machinery, negative feedback repression of CLOCK (CLK) and BMAL1 transcriptional activity by PERIOD (PER) and CRYPTOCHROME (CRY) underlies the basis for 24 h rhythmic gene expression. Thus, precise regulation of the time-dependent nuclear entry of circadian repressors is crucial to generating normal circadian rhythms. Here, we sought to identify novel kinase(s) that regulate nuclear entry of mammalian CRY1 (mCRY1) with an unbiased screening using red fluorescent protein (RFP)-tagged human kinome expression plasmids in mammalian cells. Transient expression of human vaccinia-related kinase 3 (hVRK3) reduced the nuclear presence of mCRY1. hVRK3 expression also induced alterations in the subcellular localization of other core clock proteins, including mCRY2, mPER2, and BMAL1. In contrast, the subcellular localization of mCLK was not changed. Given that singly expressed mCLK mostly resides in the cytoplasm and that nuclear localization sequence (NLS) mutation of hVRK3 attenuated the effect of hVRK3 co-expression on subcellular localization, ectopically expressed hVRK3 presumably reduces the retention of proteins in the nucleus. Finally, downregulation of hvrk3 using siRNA reduced the amplitude and lengthened the period of the cellular bioluminescence rhythm. Taken together, these data suggest that VRK3 plays a role in setting the amplitude and period length of circadian rhythms in mammalian cells.

Circadian Expression of PERIOD and the Pigment-Dispersing Factor in the yellow white mutant Drosophila melanogaster

Daily behavioral andphysiological rhythms in most animals are regulated by a circadian clock. Inthe fruit fly, Drosophila melanogaster, this clock consists of a networkof about 150 cerebral neurons. Different parameters of the fruit fly circadianlocomotion are attributed to specific neuronal subsets and the molecularrhythms of clock genes and proteins within them. To understand the clockmachinery, many clock mutant flies have been used. yellow white (y w) mutation in D. melanogaster cause impairedmelanisation, eye pigmentation loss, and behavioral alterations includingchanges in circadian locomotion. This study investigates the possible molecularbackground for these circadian alterations. Results revealed that in the outputpathway of the clock, the Pigment-Dispersing Factor (PDF) expression wassuppressed in y w mutant fruit flies compared to Canton S (CS) wild-type in the PDF+ clock neurons. Onthe other hand, the degradation of the PERIOD (PER) protein was significantlydelayed in yw mutants and their levels was higher, especially atthe transition from dark to light. The combined effect of elevated PER levelsand suppressed PDF signaling provides an explanation for the delayed morninglocomotor activity peak (M) and advanced evening peak (E) of y w fliescompared to CS.It could be concluded that mutations affecting eye pigmentation like the y w mutationcould have profound effects on the circadian regulation of behavior and theirunderlying molecular oscillations in clock neurons. These effects reduce theplasticity and robustness of the circadian clock and expose the flies to higherlevels of the environmental risk of desiccation.

HUBUNGAN BIAYA KEAGENAN, RISIKO PASAR DAN KESEMPATAN INVESTASI DENGAN KEBIJAKAN DIVIDEN: POSISI KAS SEBAGAI VARIABEL PEMODERASI

Dividend policy is a very important decision in a company. This research will analysis the correlation of agency cost, market risk, and inrestment opportunity, which is moderated with cash position , toward dividend poli cy in manufacturing companies listed in Jakarta Stock F,xchange.The variables used in this research are dependent variable which is dividend payout ratio (DPR) to proxy for dh1idend policy and independent mriable which are institutional holding to proxy for agency cost, beta to proxy for market risk, and the sales growth (GROW), market to hook 1'0/ue (M1BV), and pri ce to earnings (PER) to proxy for investment opportunity, as well as moderating l'Oriable which is cash position.The data collection is hosed on purposive sampling with 924 samples from the observable companies listed in Jakarta Stock Exchange during 1992-2001 period. The Observation is dii>ided into three period<t, which are before crisis period (1992-1996), crisis period (199 7-199R), and after crisis period (1999-2001). The result proves that institutional holding (JNSH) variable is insignificanly effect toward dividend policy. The same is BETA that is insignificanly effect toward dividend policy (DPR) for those three periods. The result of interaction hetween cash position with the sales growth to proxy investment opportunity, market to book value and price to earnings is significantly effect toward dividend policy (DPR) which means that cash position is.function as moderating variable for before crisis period (1992-1996). The result of interaction between cash position with investment opportunity for crisis peri od (1997-199R) and after crisis period (1999-2001) is insignificantly effect toward dividend policy.

Serum content of total adipionectin in the ChNPP accident clean/up workers of the «iodine period» suffering from type 2 diabetes mellitus (literature review and research data)

assay of the total adiponectin level in the ChNPP accident clean up workers (ACUW) of the «iodine peri od» exposed to ionizing radiation in a young age and suffering now from type 2 diabetes mellitusMaterials and methods. The Chernobyl Nuclear Power Plant accident clean up workers (ACUW) of the iodine period (n=111) exposed to ionizing radiation at a young age (18-35 years) were examined in two groups: Group I (main study group, n=66) of persons with type 2 diabetes mellitus (DM) and Group II (comparison group, n=45) of persons with normal glucose challenge test results. Total radiation doses varied in the range of 10.0-860.0 mSv. Group III (nosological control group, n=20) included persons suffering type 2 DM but not exposed to ionizing radiation (IR) and Group IV were apparently healthy. All study groups were representative by the age. Anthropometric data and parameters of glycemic control were assayed. Index of the homeostatic model for assessing insulin resistance (HOMA IR) was calculated. Level of total adiponectin was assayed by the immune enzyme method. Statistical pro cessing of the data was carried out using Missrosoft® Exxel 2002 software. Serum concentration of total adiponectin in the Chornobyl NPP ACUW of the iodine peri od and suffering type 2 DM despite having normal body weight or overweight or any degree of obesity was signifi cantly lower compared to apparently healthy persons ACUW with and normal glycemic control. Moderate negative correlation was found between the level of total adiponectin and degree of obesity in the ACUW suffering type 2 DM (t = 0.367, p <0.05). With an increase in the duration of the disease there was a decrease in serum concentration of total adiponectin in the Chornobyl NPP ACUW of iodine period suffering type 2 DM and in the group of nosologi cal control. The most favorable type of glycemic profile was peculiar for patients in the main group with higher lev els of total serum adiponectin and the lowest body mass index (up to 25 kg/m2). An increase in the body mass index was accompanied by an adverse combination of abnormalities in glycemic metabolism (increased glucose concen tration, IRI, and HbA1c), insulin resistance (a significant increase in HOMA) against the background of a decrease in concentration of total adiponectin. No significant differences were found in adiponectin levels in dose subgroups. At the same time, the reliable differences between the main group and comparison group were found in the 2-5th dose subgroups, which are due to differences in numbers of people with metabolic syndrome (obesity) in the groups.

Broken scale invariance in time-dependent trapping potentials

The response of a cold atom gas with contact interactions to a smoothly varying external harmonic confinement in the non-adiabatic regime is studied. The time variation of the angular frequency is varied such that the system is, for vanishing or infinitely strong contact interactions, scale invariant. The time evolution of the system with broken scale invariance (i.e., the time evolution of the system with finite interaction strength), is contrasted with that for a scale invariant system, which exhibits Efimovian-like expansion dynamics that is characterized by log-periodic oscillations with unique period and amplitude. It is found that the breaking of the scale invariance by the finiteness of the interactions leads to a time dependence of the oscillation period and amplitude. It is argued, based on analytical considerations for atomic gases of arbitrary size and numerical results for two one-dimensional particles, that the oscillation pe riod approaches that of the scale-invariant system at large times. The role of the time-dependent contact in the expansion dynamics is analyzed.

Diversification of the molecular clockwork for tissue-specific function: insight from a novel Drosophila Clock mutant homologous to a mouse Clock allele.

The circadian clock system enables organisms to anticipate the rhythmic environmental changes and to manifest behavior and physiology at advantageous times of the day. Transcriptional/translational feedback loop (TTFL) is the basic feature of the eukaryotic circadian clock and is based on the rhythmic association of circadian transcriptional activator and repressor. In Drosophila, repression of dCLOCK/CYCLE (dCLK/CYC) mediated transcription by PERIOD (PER) is critical for inducing circadian rhythms of gene expression. Pacemaker neurons in the brain control specific circadian behaviors upon environmental timing cues such as light and temperature cycle. We show that amino acids 657–707 of dCLK are important for the transcriptional activation and the association with PER both in vitro and in vivo. Flies expressing dCLK lacking AA657-707 in Clkout genetic background, homologous to the mouse Clock allele where exon 19 region is deleted, display pacemaker-neuron-dependent perturbation of the molecular clockwork. The molecular rhythms in light-cycle-sensitive pacemaker neurons such as ventral lateral neurons (LNvs) were significantly disrupted, but those in temperature-cycle-sensitive pacemaker neurons such as dorsal neurons (DNs) were robust. Our results suggest that the dCLK-controlled TTFL diversify in a pacemaker-neuron-dependent manner which may contribute to specific functions such as different sensitivities to entraining cues.

Sensory Conflict Disrupts Activity of the Drosophila Circadian Network

SummaryPeriodic changes in light and temperature synchronize the Drosophila circadian clock, but the question of how the fly brain integrates these two input pathways to set circadian time remains unanswered. We explore multisensory cue combination by testing the resilience of the circadian network to conflicting environmental inputs. We show that misaligned light and temperature cycles can lead to dramatic changes in the daily locomotor activities of wild-type flies during and after exposure to sensory conflict. This altered behavior is associated with a drastic reduction in the amplitude of PERIOD (PER) oscillations in brain clock neurons and desynchronization between light- and temperature-sensitive neuronal subgroups. The behavioral disruption depends heavily on the phase relationship between light and temperature signals. Our results represent a systematic quantification of multisensory integration in the Drosophila circadian system and lend further support to the view of the clock as a network of coupled oscillatory subunits.

P.3.a.007 - Disturbed DISC1 pathway interacts with adolescent cannabis exposure to produce impaired recognition memory restored by BDNF over-expression: a host-environment mouse model of severe mental illness

The same clock-genes, including Period (PER) 1 and 2, that show rhythmic expression in the suprachiasmatic nucleus (SCN) are also rhythmically expressed in other brain regions that serve as extra-SCN oscillators. Outside the hypothalamus, the phase of these extra-SCN oscillators appears to be reversed when diurnal and nocturnal mammals are compared. Based on mRNA data, PER1 protein is expected to peak in the late night in the paraventricular nucleus of the hypothalamus (PVN) of nocturnal laboratory rats, but comparable data are not available for a diurnal species. Here we use the diurnal grass rat (Arvicanthis niloticus) to describe rhythms of PER1 and 2 proteins in the PVN of animals that either show the species-typical day-active (DA) profile, or that adopt a night-active (NA) profile when given access to running wheels. For DA animals housed with or without wheels, significant rhythms of PER1 or PER2 protein expression featured peaks in the late morning; NA animals showed patterns similar to those expected from nocturnal laboratory rats. Since the PVN is part of the circuit that controls pineal rhythms, we also measured circulating levels of melatonin during the day and night in DA animals with and without wheels and in NA wheel runners. All three groups showed elevated levels of melatonin at night, with higher levels during both the day and night being associated with the levels of activity displayed by each group. The differential phase of rhythms in the clock-gene protein in the PVN of diurnal and nocturnal animals presents a possible mechanism for explaining species differences in the phase of autonomic rhythms controlled, in part, by the PVN. The present study suggests that the phase of the oscillator of the PVN does not determine that of the melatonin rhythm in diurnal and nocturnal species or in diurnal and nocturnal chronotypes within a species.

A5230 - Influence and effects of the diet and bariatric surgery on the biological clock of peripheral tissues

One area of considerable interest is the degree to which eating patterns influence energy regulation and the risk of obesity. Animal studies have indicated that the timing of food intake may be linked to energy regulation. The vast majority of research on eating patterns among humans has focused on breakfast skipping versus consumption, particularly in children. Although the data are not completely consistent, most studies have concluded that, among children, skipping breakfast is associated with a higher risk of obesity, as well as lower overall diet quality and poorer cognitive performance. Dysregulation of nutrient availability can have an impact on survival during a fast or lead to obesity and related pathologies, such as type 2 diabetes, in response to overnutrition. The meal times (and number of meals consumed) differ greatly from culture to culture and through time. Indeed, timing of food intake is a modifiable behavior that may influence energy regulation and consequently the risk of obesity. A number of recent studies in animals have linked energy regulation and the circadian clock at the molecular, physiological and behavioral levels, findings that raise the possibility that the timing of food intake itself may play a significant role in weight gain. The aim of this study was to test the hypothesis that significant and sustained weight loss, induced by bariatric surgery and diet could modify the expression of clock genes, metabolism and physiology ones on human stomach Stomach explants from morbilidly patients with obesity disease obtained during bariatric surgery, were taken and placed into 24-well plates with DMEM and kept in an incubator at 37ºC for 1h to stabilize the tissues. After that, the explants were incubated with DMEM or oleic acid 100 µM during 6h and change every 6h for a full day. The samples considered control, remained overnight with DMEM.The samples with oleic acid remained the 6h but not continously, each test samples were kept treatment according to the time show:Time 0= initial timeTime 21h or 9pmTime 3h or 3amTime 9h or 9amTime 15h or 3pm Several epidemiological studies have suggested that the perturbation of circadian rhythm has adverse metabolic consequences (e.g., dyslipidemia) in humans. At the molecular level, circadian rhythms are encoded by an autoregulatory loop composed of a set of transcription activators (BMAL1 Brain and Muscle Arnt Like 1/CLOCK (Circadian Locomotor Output Cycles Kaput) that induce expression of repressors (PER (period) /CRY (cryptocromo).The mammalian molecular clock is not only expressed within the master suprachiasmatic nucleus pacemaker neurons, but also within nearly all cells. We have identify clock genes presence on stomach. The clock genes on the stomach tissue are regulated by oleic acid and by bariatric surgery. Not only the amount or type of food we ingest, but also the timing of food consumption seems to play a crucial role in the development of obesity and associated metabolic disorders. Circadian clocks are widely accepted to act as the timekeeping system of nearly every living organism, ensuring that physiological processes are carried out at the right time of day or night.However, the concept that the stomach is home to one of the food-entrainable oscillators that predicts the availability of food, especially when food becomes restricted, is the first time that is reported to be a peripheral clock.

Does exercise training impact clock genes in patients with coronary artery disease and type 2 diabetes mellitus?

Recent findings revealed negative effects of deregulated molecular circadian rhythm in coronary artery disease (CAD) and type 2 diabetes mellitus (T2DM). Physical exercise training (ET) has been shown to promote anti-diabetic and anti-atherogenic responses in skeletal muscle of these patients, but the role of the circadian clock-machinery remains unknown. This study investigated whether mRNA expression of clock genes in skeletal muscle of CAD and T2DM patients is influenced by physical ET intervention. Nineteen patients with CAD and T2DM (age 64 ± 5 years) were randomised to either six months of ET (four weeks of in-hospital ET followed by a five-month ambulatory programme) or usual care. At the beginning of the study, after four weeks and after six months parameters of metabolic and cardiovascular risk factors, and physical exercise capacity were assessed. Gene expression was measured in skeletal muscle biopsies by quantitative real-time polymerase chain reaction (PCR). A selection of clock genes and associated components (circadian locomoter output cycle kaput protein (CLOCK), period (PER) 1, cryptochrome (CRY) 2 and aminolevulinate-deltA-synthase-1 (ALAS1)) was reliably measured and used for further analysis. A time-dependent effect in gene expression was observed in CLOCK (p = 0.013) and a significant interaction between time and intervention was observed for ALAS1 (p = 0.032; p = 0.014) as a result of ET. This is the first study to analyse clock gene expression in skeletal muscles of patients with CAD and T2DM participating in a long-lasting exercise intervention. ET, as one of the cornerstones in prevention and rehabilitation of CAD and T2DM, exerts no effects on CLOCK genes but meaningful effects on the clock-associated gene ALAS1.

Temporal Expression of the Clock Genes in the Water Flea Daphnia pulex (Crustacea: Cladocera).

The timekeeping mechanisms that operate at the core of circadian clocks (oscillators) are based on interacting molecular feedback loops consisting of clock and clock-associated genes. However, there is a lack of comprehensive studies on the expression of clock genes (particularly those forming its core) in single crustacean species at the mRNA and protein levels, and these studies could serve as a basis for constructing a model of the crustacean molecular oscillator. Studies on Daphnia pulex are well suited to fill this gap because this species is the only representative crustacean whose genome has been sequenced. We analyzed the abundance of 20 gene transcripts throughout the day in the whole bodies of D. pulex (single clone); we found that 15 of these genes were transcriptionally active, and most had daily expression level changes. According to the functional classification of their homologues in insects, these genes may represent elements of the Daphnia molecular oscillator core and its input and output pathways. Studies of PERIOD (PER) protein, one of the main clock components, revealed its rhythmic expression pattern in the epidermis, gut, and ovaries. Finally, the cycling levels of many of these clock components observed in animals reared in continuous light led to the conclusion that the Daphnia oscillator, even if it is structurally similar to the oscillators of other arthropods, can be considered a particularly important adaptive mechanism for living in environments with extreme photoperiods.

Identification of Light-Sensitive Phosphorylation Sites on PERIOD That Regulate the Pace of Circadian Rhythms in Drosophila.

The main components regulating the pace of circadian (≅24 h) clocks in animals are PERIOD (PER) proteins, transcriptional regulators that undergo daily changes in levels and nuclear accumulation by means of complex multisite phosphorylation programs. In the present study, we investigated the function of two phosphorylation sites, at Ser826 and Ser828, located in a putative nuclear localization signal (NLS) on the Drosophila melanogaster PER protein. These sites are phosphorylated by DOUBLETIME (DBT; Drosophila homolog of CK1δ/ε), the key circadian kinase regulating the daily changes in PER stability and phosphorylation. Mutant flies in which phosphorylation at Ser826/Ser828 is blocked manifest behavioral rhythms with periods slightly longer than 1 h and with altered temperature compensation properties. Intriguingly, although phosphorylation at these sites does not influence PER stability, timing of nuclear entry, or transcriptional autoinhibition, the phospho-occupancy at Ser826/Ser828 is rapidly stimulated by light and blocked by TIMELESS (TIM), the major photosensitive clock component in Drosophila and a crucial binding partner of PER. Our findings identify the first phosphorylation sites on core clock proteins that are acutely regulated by photic cues and suggest that some phosphosites on PER proteins can modulate the pace of downstream behavioral rhythms without altering central aspects of the clock mechanism.

Polymorphisms in period genes and bone response to hormone therapy in postmenopausal Korean women

ABSTRACTObjective In this study, we aimed to explore the association between polymorphisms in the period (PER) gene and bone response to hormone therapy (HT) in postmenopausal Korean women.Methods The PER1 c.2284C > G, c.2247C > T, PER2 c.3731G > A, PER3 c.2592G > A, c.3083T > C polymorphisms, and PER3 54bp variable number of tandem repeats (VNTR) were analyzed in 509 postmenopausal Korean women who received HT. Bone mineral density (BMD) at the lumbar spine and femoral neck before and after 1 year of HT and serum levels of osteoprotegerin (OPG), soluble receptor activator of the nuclear factor-κB ligand (sRANKL) and bone turnover markers were measured after 6 months of HT.Results The PER1 c.2884 C > G polymorphism and PER3 54bp VNTR were associated with annual percent changes in BMD of the femoral neck after 1 year of HT (p < 0.05). Changes in BMD at the femoral neck in the non-CC genotype of the PER1 c.2884C > G polymorphism and in the 4-repeat homozygote of PER3 54bp VNTR were significantly lower than those in CC genotype and non-4-repeat homozygote, respectively. The PER1 c.2884C > G polymorphism was associated with the non-response (>3% BMD loss/year after HT) of HT. The non-CC genotype of the PER1 c.2884C > G polymorphism showed a 1.92-times higher risk of non-response at the lumbar spine and/or femoral neck (p = 0.01) compared with the CC genotype. No significant changes in bone markers after 6 months of HT were noted according to the PER1 c.2884C > G polymorphism.Conclusions The PER1 c.2884C > G polymorphism may be associated with risk of non-response to HT in postmenopausal Korean women.

A Period2 Phosphoswitch Regulates and Temperature Compensates Circadian Period

Period (PER) protein phosphorylation is a critical regulator of circadian period, yet an integrated understanding of the role and interaction between phosphorylation sites that can both increase and decrease PER2 stability remains elusive. Here, wepropose a phosphoswitch model, where two competing phosphorylation sites determine whether PER2 has a fast or slow degradation rate. This mathematical model accurately reproduces the three-stage degradation kinetics of endogenous PER2. We predict and demonstrate that the phosphoswitch is intrinsically temperature sensitive, slowing down PER2 degradation as a result of faster reactions at higher temperatures. The phosphoswitch provides a biochemical mechanism for circadian temperature compensation of circadian period. This phosphoswitch additionally explains the phenotype of Familial Advanced Sleep Phase (FASP) and CK1ε(tau) genetic circadian rhythm disorders, metabolic control of PER2 stability, and how drugs that inhibit CK1 alter period. The phosphoswitch provides a general mechanism to integrate diverse stimuli to regulate circadian period.

Drosophila peptidyl-prolyl isomerase Pin1 modulates circadian rhythms via regulating levels of PERIOD

In animal circadian clock machinery, the phosphorylation program of PERIOD (PER) leads to the spatio-temporal regulation of diverse PER functions, which are crucial for the maintenance of ∼24-hr circadian rhythmicity. The peptidyl-prolyl isomerase PIN1 modulates the diverse functions of its substrates by inducing conformational changes upon recognizing specific phosphorylated residues. Here, we show that overexpression of Drosophila pin1, dodo (dod), lengthens the locomotor behavioral period. Using Drosophila S2 cells, we demonstrate that Dod associates preferentially with phosphorylated species of PER, which delays the phosphorylation-dependent degradation of PER. Consistent with this, PER protein levels are higher in flies overexpressing dod. Taken together, we suggest that Dod plays a role in the maintenance of circadian period by regulating PER metabolism.

Impact of futures trading on spot prices of mustard in the state of Rajasthan

In this investigation an attempt has been made to study the impact of futures trading on spot prices of mustard seed in the state of Rajasthan. For this purpose secondary data on futures prices collected from the annual reports of the commodity exchange for the financial years 2003 to 2008 and on spot prices collected from Krishi Upaj Mandi, Bikaner for the financial years 2000 to 2008 were used. The period prior to futures trading was designated as pre futures period (PI) and that of futures trading as futures period (PII). Growth in monthly prices was estimated with the help of exponential function and trend by fitting of quadratic function. Impact of futures trading on spot prices was captured by employing dummy variable technique. Integration among futures and spot markets was studied by computing simple correlation between prices. All the prices – futures, spot market and mandi spot prices for mustard seed recorded significant growth of the order of 0.57 per cent, 0.42 per cent and 0.43 per cent, respectively, during the study period. The trend in all these prices of mustard seed was noted to be curvi linear in shape during the study period, i.e., concave downwards. The significantly high value of ‘F’ statistic for mustard seed suggested that T and T2 jointly had significant effect on prices (P). The study also revealed that the futures trading affected the slope of spot prices of mustard seed, i.e., rate of change in the spot prices, without affecting the mean price level. This meant that the regressions were concurrent in nature. Thus it may be inferred that futures prices of mustard reduced the rate of change in the spot prices of the crop in the futures period. The futures market and the spot market were noted to be highly integrated (0.9140) in respect of the mustard seed.

Molecular Cloning, Sequence Analysis, and Gene Expression of the Circadian Clock GenePeriodinCulex quinquefasciatusSay (Diptera: Culicidae)

In prokaryotes and eukaryotes, the Period (PER) gene is important for the circadian clock that regulates some rhythmic biochemical, physiological, and behavioral processes. PER messenger amplification was done by RT-PCR from southern house mosquito, Culex quinquefasciatus Say, larvae collected at three locations in the State of Nuevo Leon, northeastern Mexico. The amplified products were cloned, sequenced, and compared/analyzed with those of other species of mosquitoes. A 3,093-bp amplified product was synthesized by PCR, which is the complete coding DNA sequence (3,027 bp) of PER encoding an open reading frame of 996 amino acid residues and much smaller than the orthologous in other mosquitoes analyzed. No other simultaneous amplification was visualized; thus, possible alternative splicings were discarded or at least not detected by the method. Because PER is a widely conserved gene in prokaryotes and eukaryotes and maintaining colonies of southern house mosquitoes is relativity easy, determining the sequence of the gene in the mosquito provides the possibility of using the gene as a model and generating data on the role in the circadian clock.

Drosophila TIM Binds Importin α1, and Acts as an Adapter to Transport PER to the Nucleus

Regulated nuclear entry of clock proteins is a conserved feature of eukaryotic circadian clocks and serves to separate the phase of mRNA activation from mRNA repression in the molecular feedback loop. In Drosophila, nuclear entry of the clock proteins, PERIOD (PER) and TIMELESS (TIM), is tightly controlled, and impairments of this process produce profound behavioral phenotypes. We report here that nuclear entry of PER-TIM in clock cells, and consequently behavioral rhythms, require a specific member of a classic nuclear import pathway, Importin α1 (IMPα1). In addition to IMPα1, rhythmic behavior and nuclear expression of PER-TIM require a specific nuclear pore protein, Nup153, and Ran-GTPase. IMPα1 can also drive rapid and efficient nuclear expression of TIM and PER in cultured cells, although the effect on PER is mediated by TIM. Mapping of interaction domains between IMPα1 and TIM/PER suggests that TIM is the primary cargo for the importin machinery. This is supported by attenuated interaction of IMPα1 with TIM carrying a mutation previously shown to prevent nuclear entry of TIM and PER. TIM is detected at the nuclear envelope, and computational modeling suggests that it contains HEAT-ARM repeats typically found in karyopherins, consistent with its role as a co-transporter for PER. These findings suggest that although PER is the major timekeeper of the clock, TIM is the primary target of nuclear import mechanisms. Thus, the circadian clock uses specific components of the importin pathway with a novel twist in that TIM serves a karyopherin-like role for PER.

Self-Medication with Antibiotics amongst Civil Servants in Uyo, Southern Nigeria

Background: Self - medication with antibiotics constitute a major form of irrational use of medicines and can cause significant adverse effects such as resistant microorganisms, treatment failure, drug toxicity, increase in treatment costs, prolong hospitalization peri od and increase in morbidity. Objective: To estimate the prevalence of self - medication with antibiotics and evaluate the socio demographic factors associated with the practice of self - medication with antibiotics among civil servants in Uyo, southern Nigeri a. Methods: A cross sectional survey using self - administered, structured, validated and pre - tested questionnaires consisting of open and closed ended questions. 526 of these questionnaires were randomly distributed to civil servants working in the Akwa Ibo m state civil service secretariat, Uyo. Results: The prevalence of self - medication observed in this study is 93.9%. The most commonly used antibiotics in self - medication were ampicillin/cloxacillin 133 (28.3%), metronidazole 130 (27.6%), co - trimoxazole 70 (14.9%), ciprofloxacin 69 (14.6%), and amoxicillin 46 (10%). The most frequent reason given by respondents for indulging in self - medication with antibiotics was