Interval Of Several Days Research Articles

The Reproducibility of Cardiovascular Response to a Mental Task

The present study investigated the reproducibility of cardiovascular responses by presenting a mental task to eight healthy subjects four times at intervals of one year and of several days. Subjects performed a mental subtraction task at the same time of day and under the same conditions. For each experiment day, systolic and diastolic blood pressure (SBP and DBP), mean arterial pressure (MAP), cardiac output (CO), heart rate (HR), stroke volume (SV), and total peripheral resistance (TPR) were measured for a 5-minute baseline period, a 5-minute task period, and a 10-minute recovery period. To examine the reproducibility of cardiovascular response, two-way factorial ANOVA (subject factor and experiment day factor) was conducted, and the intra-class correlation coefficient (ICC) was calculated. The results showed that there were no significant differences between experiment days separated by one year or between those separated by several days for all indexes. The ICCs were high for blood pressures (SBP, DBP and MAP, ICCs>0.8) and cardiac responses (HR, SV, and CO, ICCs>0.7) for both the interval of one year and that of several days. For the total peripheral resistance, ICC was only high at the interval of several days (>0.7). In conclusion, the reproducibility of the blood pressure response to a mental task was proven, and in case of the changed blood pressure, the cardiac responses were also reproduced for intervals of one year and of several days.

Computational modeling and empirical studies of hippocampal neurogenesis-dependent memory: Effects of interference, stress and depression

Prolonged stress causes dysregulation in the hypothalamic-pituitary-adrenal axis and may contribute to the pathogenesis of major depressive disorder (MDD). MDD is associated with pathological changes in several brain regions, particularly the prefrontal cortex and hippocampus. Evidence from animal research suggests that one of the earliest signs of pathological change after exposure to stress is a reduction in hippocampal neurogenesis. We therefore sought to test the prediction that people in the earliest stages of a first episode of depression would show selective memory deficits on neurogenesis-dependent tasks. Our computational model predicts that new neurons are important for representing distinct contexts; thus, when overlapping memories are learned over an interval of several days, during which time some neuronal turnover has taken place, the neurogenesis should reduce the potential for interference between the overlapping memories. At much shorter time scales, within the span of a single memory episode, rather than contributing to pattern separation, neurogenesis might play more of an integrative role in mediating contextual associative learning. Consistent with this, empirical evidence from animal studies suggests a role for the new neurons in forming complex event memories that bridge across time delays. This leads us to predict selective memory deficits on putative neurogenesis-dependent tasks in the earliest pre-clinical stages of a first episode of depression, before a clinical diagnosis has been made and prior to the development of more serious pathological brain changes. We present the results of new simulations with the model, lending further support to the prediction that neurogenesis reduces interference when memory events are separated by several days. We also report findings from an empirical study in which we tested a large number of undergraduates on a set of cognitive and memory tests from the CANTAB battery, and also administered neuropsychological inventories for stress, depression and anxiety. One of the subtests in the CANTAB battery, the delayed match to sample (DMS) task, was of particular interest as delayed non-match to sample has been found in animal studies to be dependent upon neurogenesis. Our empirical results indicate that as predicted, participants scoring high on the Beck Depression Inventory show a selective deficit on the DMS at long delays while performing on par with non-depressed participants on all other tasks. The potential to detect very early signs of major depression using simple neurogenesis-dependent cognitive tests could have important implications for the diagnosis and treatment of this debilitating and highly prevalent disorder.

Gonadal Cycle ofTegula eiseni(Jordan1936) (Mollusca: Gastropoda) in Bahía Asunción, Baja California Sur, Mexico

ABSTRACT The gonadal cycle of Tegula eiseni (Jordan, 1936) was determined on monthly samples (25–30 organisms) collected from a population in Bahia Asuncion, B.C.S., from January 2006 to December 2006. The results of the histological study indicate that both males and females show stages of gametogenesis and gonad maturation throughout the year and only two major spawning events: one in spring and another in fall. The species behaved as a partial spawner, and only at certain times was total spawning observed in females. Maturation and release or spawning times seem to be closely related to seasonal temperature rises and abrupt changes in surface sea water temperature, which occur at brief intervals for several days at certain times of year.

Synergistic decrease in blood pressure by captopril combined with losartan in spontaneous hypertensive rats

This study was designed to examine the anti-hypertensive effect of the combination therapy of captopril with losartan by oral administration using both independent and cross-over experimental protocols. In independent experimental protocols, four different groups of spontaneous hypertensive rats (SHR) were treated for 1 or 2 weeks: control, captopril (20 mg/kg/day), losartan (20 mg/kg/day), and combination captopril (10 mg/kg/day) with losartan (10 mg/kg/day). In cross-over protocols, each SHR received all four treatments for 1 or 3 days with an interval of several days between each injection for washing-out and return to high blood pressure (BP) levels. BP and heart rate (HR) were measured in conscious telemetered SHR. According to the results from the independent protocol, regardless of a 1- or 2-week administration period, combination therapy with low doses of captopril and losartan had a greater anti-hypertensive effect than individual high-dose monotherapy. Similarly, results from the cross-over protocol showed that regardless of 1-day or 3-day administration, the decrease in BP in the 11(th) and 12(th) hour after administration was greatest with the combination of low-dose captopril and losartan. Therefore, combination therapy with low doses of captopril with losartan lowered BP to a greater extent than a high dose of either individual monotherapy.

Tumor Selectivity at Short Times Following Systemic Administration of a Liposomal Temoporfin Formulation in a Murine Tumor Model

Meso-tetra(hydroxyphenyl)chlorin (mTHPC) (INN: Temoporfin) is one of the most potent photodynamically active substances in clinical use. Treatment protocols for Temoporfin-mediated photodynamic therapy often rely on drug-light intervals of several days in order for the photosensitizer to accumulate within the target tissue, though tumor selectivity is limited. Here, the mTHPC localization was studied at 2-8 h following systemic administration of a liposomal Temoporfin formulation (0.15 mg kg(-1) b.w.) in HT29 human colon adenocarcinoma in NMRI nu/nu mice. Photosensitizer distribution within tumor and internal organs was investigated by means of high performance liquid chromatography following chemical extraction, as well as in situ fluorescence imaging and point-monitoring fluorescence spectroscopy. For tumor tissue, the Temoporfin concentrations at 4 h (0.16+/-0.024 ng mg(-1)) and 8 h (0.18+/-0.064 ng mg(-1)) were significantly higher than at 2 h (0.08+/-0.026 ng mg(-1)). The average tumor-to-muscle and the tumor-to-skin selectivity were 6.6 and 2, respectively, and did not vary significantly with time after photosensitizer injection. In plasma, the Temoporfin concentration was low (0.07+/-0.07 ng mg(-1)) and showed no significant variation with time. Our results indicate a rapid biodistribution and clearance from the bloodstream. Within the same type of organ, data from both fluorescence methods generally exhibited a significant correlation with the extraction results.

MOUND AND MATE CHOICE IN A POLYANDROUS MEGAPODE: FEMALES LAY MORE AND LARGER EGGS IN NESTING MOUNDS WITH THE BEST INCUBATION TEMPERATURES

Abstract Males of the polyandrous Australian Brush-turkey (Alectura lathami) build mounds of leaf litter, in which incubation heat is produced by microbial decomposition. Females lay eggs singly, at intervals of several days, over many months. For each egg, they select an incubation mound in which to lay, and they then typically copulate with the male mound-owner; mound choice is, thus, usually equal to mate choice. Freed from incubation and maternal care, these females can invest considerable time and energy in assessing and choosing their potential mates. Low or high incubation temperatures inside the mounds have negative effects on embryos and chicks, and temperatures vary considerably both between and within mounds. Here, I show that mounds with mean incubation temperatures ranging from approximately 32°C to 35°C received more eggs than cooler or warmer mounds. Similarly, when the size of each egg was compared with its temperature when found in the mound, larger eggs were deposited mainly in mound mat...

Mound and Mate Choice in a Polyandrous Megapode: Females Lay More and Larger Eggs in Nesting Mounds With the Best Incubation Temperatures

AbstractMales of the polyandrous Australian Brush-turkey (Alectura lathami) build mounds of leaf litter, in which incubation heat is produced by microbial decomposition. Females lay eggs singly, at intervals of several days, over many months. For each egg, they select an incubation mound in which to lay, and they then typically copulate with the male mound-owner; mound choice is, thus, usually equal to mate choice. Freed from incubation and maternal care, these females can invest considerable time and energy in assessing and choosing their potential mates. Low or high incubation temperatures inside the mounds have negative effects on embryos and chicks, and temperatures vary considerably both between and within mounds. Here, I show that mounds with mean incubation temperatures ranging from approximately 32°C to 35°C received more eggs than cooler or warmer mounds. Similarly, when the size of each egg was compared with its temperature when found in the mound, larger eggs were deposited mainly in mound material at temperatures between approximately 32°C and 35°C, whereas smaller eggs were laid at temperatures above and below this range. Egg size was included as a factor describing female mate choice, because egg size in relation to body size is exceptionally large, which indicates considerable female investment. Overall, these results suggest that the temperature in the males’ incubation mounds considerably affects female mate choice.Selección del Montículo y de la Pareja en un Megápodo Poliándrico: Las Hembras Ponen Más y Mayores Huevos en los Montículos de Nidificación con las Mejores Temperaturas de Incubación

Deformable registration for image-guided radiation therapy

Ths paper examines several applications of deformable registration algorithms in the field of image-guided radiotherapy. The first part focuses on the description of input and output of deformable registration algorithms, with a brief review of conventional and most current methods. The typical applications of deformable registration are then reviewed on the basis of four practical examples. The first two sets of examples deal with the fusion of images obtained from the same patient (inter-fraction registration), with time intervals of several days between each image. The other two examples deal with the fusion of images obtained in immediate sequence (intra-fraction registration); in this case, the focus is the displacement during image acquisition or patient treatment (mainly due to respiratory movement), with time intervals in the order of magnitude of tenths of seconds. Finally, the registration of images of different patients (inter-patient registration) is also discussed.In conclusion, deformable registration has become a fundamental tool for image analysis in radiotherapy. Although extensive validation of the numerous existing methods is required before extending its clinical use, deformable registration is expected to become a standard methodology in the treatment planning systems in the near future.

Effects of atmospheric CO2 enrichment and sunlight on degradation of plant particulate and dissolved organic matter and microbial utilization

Particulate and dissolved organic matter were generated from foliage of the emergent macrophyte Typha latifolia and the riparian tree Populus tremuloides grown both under ambient (AMB, 360 μl L -1 ) and elevated (ELEV; 720 μl L -1 ) atmospheric CO 2 concentrations. Percentage lignin, C: N ratios, and percentage total phenolic compounds were significantly higher (15-100%) in live and senescent plant tissues grown in ELEV than in AMB CO 2 conditions. Fungal biomass and rates of growth were 25 % and 50 % lower on the more recalcitrant particulate organic matter of ELEV Populus and Typha, respectively, both of which had appreciably lower N content than tissues of AMB grown plants. Bacterial development on the surfaces of ELEV tissues was nearly an order of magnitude lower than on AMB grown tissues. Leaching of dissolved organic carbon (DOC) was greater from ELEV CO 2 -grown leaves than those grown on AMB CO 2 . Bacterial production rates on leachates from Populus were much higher than those from Typha, and rates were significantly lower on those released from tissues from both species grown on elevated CO 2 . Leaves of the different plant species were allowed to decompose for up to 13 weeks under natural conditions. At specific intervals, supernatant leachate DOC was removed, sterilized by filtration, and exposed to natural light (full sunlight or PAR without UV). Simple organic substrates or CO 2 generated photolytically were determined and the effects of the products on bacterial productivity were assayed at intervals for several days. Complete photolytic mineralization to CO 2 of DOC freshly released (24 hr) from both plant species was higher (ca. 35 %) from plants grown on ELEV than from AMB CO 2 . After longer periods of decomposition of leaves and leachates, photolytic mineralization of DOC to CO 2 was reduced but that from ELEV-grown tissues was still greater than from AMB. Citric, acetic, malic, formic and other acids were cleaved from humic macromolecules by short (<6hr) exposures to sunlight. Although PAR was not as effective as full sunlight with UV components, photolytic generation of fatty acids by PAR was clearly a major photodegradation process. Bacterial production was always significantly enhanced by brief (< 6 hr) exposure of leachates to either full sunlight or to PAR only.

A new species of Peripatopsis from South Africa, P. stelliporata, with observations on embryonic development and sperm degradation (Onychophora, Peripatopsidae)

Abstract Peripatopsis stelliporata sp. nov. from South Africa is described. SEM observations are used to illustrate the similarities and differences between this species and Peripatopsis capensis Grube 1866. The most conspicuous differences in morphology between the two species relate to the structure of the last reduced pair of legs, and the male genital pore, which in P. stelliporata is stellate in shape. Maintaining P. stelliporata in culture allowed timings of births to be recorded and the onset of sexual maturity to be determined. Spermatophores were first noted when the males were c. 4 months old. Females were observed to give birth at 15 months of age. In any female the embryos are all at around the same stage of development, and females gave birth between February and May. Young were born singly or in pairs at intervals of several days. The appearance of the embryos of P. stelliporata and also those of P. capensis collected in 1996 and 1997 was unexpected, as they are transparent apart from the red pigmented gut running from the mouth to the anus. Previously observed embryos of P. capensis were opaque and unpigmented. In appearance these embryos have similarities to those of Opisthopatus cinctipes Purcell 1895, which exhibits a different pattern of embryonic development. Whether or not this difference in appearance of the embryos reflects a transition in the pattern of development is discussed. A modified key for South African Peripatopsidae incorporating P. stelliporata is presented.

On the radio emission of the preflare active regions

This work is devoted to the new phenomena appearing in radio emission in preflare active regions that were found with the use of radio telescope RATAN-600. The first is the complicated spectral-polarization behavior in narrow frequency range and, in particularly, the double changing of the polarization emission sign in active region at the time interval of several days before big flare. The second, the detection of regular decreasing of radio brightness radio darkening of active regions, which is also observed in a few days prior to flare [Tokhchukova &amp; Bogod (2003)].To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Long-range temporal correlations in alpha and beta oscillations: effect of arousal level and test–retest reliability

Objective: The aim of the present study was to evaluate test–retest reliability and condition sensitivity of long-range temporal correlations in the amplitude dynamics of electroencephalographic alpha and beta oscillations. Methods: Twelve normal subjects were measured two times with a test–retest interval of several days. Open- and closed-eyes conditions were used, representing different levels of arousal. The amplitude of the alpha and beta oscillations was extracted with bandpass filtering and the Hilbert transform. The long-range temporal correlations were quantified with detrended fluctuation analysis. Results: The amplitude dynamics of the alpha and beta oscillations demonstrated power-law long-range temporal correlations lasting for tens of seconds. These correlations were degraded in the open- compared to the closed-eyes condition. Test–retest statistics demonstrated that the long-range temporal correlations had significant reliability, which was greatest in the closed-eyes condition. Conclusions: The presence of long-range temporal correlations indicates that the amplitude of neuronal oscillations at a given time is dependent on the amplitude at times as remote in the past as tens of seconds. The reliability of long-range temporal correlations suggests that the mechanisms generating the amplitude fluctuations are not perturbed over several days. The systematic changes in the scaling exponents at different levels of arousal indicate that these changes occur on many time scales (5–80 s) as a result of modifications in the intrinsic dynamics of the neuronal oscillations. Significance: This study demonstrates that the dynamics of spontaneous neuronal oscillations possess long-range temporal correlations with properties suitable for functional and clinical studies.

Is Monogamy in the Polynesian Megapode (Megapodius Pritchardii) Related to its High Relative Egg-Weight?

AbstractParental care is regarded as one of the most influential forces acting on the evolution of mating systems. Polynesian Megapodes (Megapodius pritchardii) are burrow nesters and rely on geothermal heat for incubation. Because they provide no parental care, either before or after hatching, they can provide insights into selective forces that have shaped mating systems in the absence of parental care. Our study of their mating system—the first such study of any burrow-nesting megapode—suggests social monogamy. The partners of 10 marked pairs stayed together in the same territory for ≤12 months and were seen with their partner significantly more often than on their own. In 64% of all observations, pair partners foraged &lt;5 m apart, and females fed on food items uncovered by the male. Duets also indicated long-lasting pair bonds. We propose that monogamy in this species is related to the fact that females lay only one large egg at a time (which weighs, on average, 24% of her body weight), in intervals of several days or weeks. Producing eggs year-round, females require a high intake of protein-rich food. They seem to benefit, within the pair bond, from the male-defended feeding territory and from the invertebrates the male uncovers while feeding close by. While being guarded by the male, females can spend more time searching for food and are protected from forced copulations by other males. The monogamous pair bond seems to benefit the male by enhancing his chances of fertilizing his partner's eggs; with an unpredictable laying interval and year-round egg production, males cannot predict when their partner will be fertile and thus benefit from staying with her year-round.

The effect of the nonspecific nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester on the choroidal compensatory response to myopic defocus in chickens.

Chick eyes show rapid compensation to retinal defocus. One component of this mechanism involves changes in the thickness of the choroid: when the retina is exposed to myopic defocus, the choroid thickens, pushing the retina forward; conversely, when the eye is exposed to hyperopic defocus, the choroid thins. The underlying mechanism(s) for these changes are unknown. We tested the hypothesis that nitric oxide might play a role. We examined the effect of the nonspecific nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) on the compensatory choroidal thickening in response to myopic defocus using two visual paradigms: first, in previously form-deprived "recovering" eyes and, second, in eyes wearing +15 D spectacle lenses. L-NAME was injected intravitreally after removal of the diffuser or immediately before putting on the lenses. In addition, we looked at the effect of L-NAME on experimentally thickened choroids (induced by 1 week of recovery from deprivation myopia or 1 week of +15 D lens wear) and on choroids of normal eyes. Eyes were measured using A-scan ultrasonography before the injections and at subsequent intervals for several days. As a control for the injection procedure, eyes with the same visual conditions were injected with saline. Fellow eyes were untreated and uninjected. L-NAME inhibited choroidal thickening in both previously form-deprived eyes (2 vs. 117 microm; p < 0.001) and eyes wearing +15 D lenses (3 vs. 137 microm; p < 0.02). The effect was rapid, transient, and dose dependent (ED50, 0.26 micromoles). L-NAME produced thinning in experimentally thickened choroids (recovering: -116 microm; lenses: -219 microm) and in normal choroids (-47 microm) within 7 hours. Nitric oxide may play a role in modulating choroidal thickness. The mechanism is as yet unknown.

Fluoxetine and Sleep EEG: Effects of a Single Dose, Subchronic Treatment, and Discontinuation in Healthy Subjects

The goals of the current study were to evaluate whether a single dose of fluoxetine causes qualitatively different changes in sleep architecture and NREM sleep EEG than subchronic administration in healthy subjects and to determine degree and duration of such changes after the single dose and after discontinuation from subchronic administration. Our hypothesis was that subchronic intake should cause changes qualitatively different from the single dose and that such changes could be sufficiently long-lived to suggest the possibility of a dosing in intervals of several days. Ten healthy volunteers first took one single 60-mg dose of fluoxetine and a week later started to take a 40-mg dose every morning for three weeks. Sleep laboratory nights included two nights before and four nights after the single dose and every second night for two weeks after discontinuation from subchronic administration. The single dose caused only a slight increase in drug plasma concentrations but relatively clear changes in sleep structure. After discontinuation from subchronic administration, sleep quality indices normalized quickly (within 2–4 days), whereas REM latency and spectral power effects correlated with total SSRI plasma concentration and normalized more slowly, corresponding to the drug plasma half-life of about 10 days. The REM fraction of the sleep period showed a rebound, whereas the delta sleep ratio did not correlate with drug plasma levels and yet remained increased after the medication interval. Thus, the only qualitative difference seen between acute and subchronic medication was the initial sleep disturbance. REM latency and especially the delta sleep ratio remained increased for several days after discontinuation from subchronic administration, indicating the possibility of a less-than-daily maintenance medication after an initial daily interval. Finally, the pattern of change observed for the delta sleep ratio indicates that it may be due to secondary, adaptive effects possibly linked to the antidepressant effect of fluoxetine in depressed patients.

Diffusion of99Tc in granite: A small scale laboratory simulation experiment

The diffusion of99Tc in granite was investigated with small-sized diffusion cells, composed of a radioactive source solution cell and a sampling cell. Water in the two cells was kept at the same level. 1 ml aliquots were taken from the sampling cells daily during the first 50 days, then at intervals of several days, and measured via liquid scintillation counting. The experimental results indicate that the diffusion of99Tc and3H in granite follows the one-dimensional diffusion equation when diffusion time is long enough (&gt;100 days). The calculated average diffusion coefficient of99Tc (1.4×10-12m2/s) is about one half of that of3H (3.2×10-12m2/s).

Cerebroside synthesis as a measure of the rate of remyelination following cuprizone-induced demyelination in brain.

We studied markers of myelin content and of the rate of myelination in brains of mice between 8 and 20 weeks of age. During the 12-week time-course, control animals showed slight increases in the content of oligodendroglial-specific cerebroside, as well as cholesterol (enriched in, but not specific to, myelin). In contrast, synthesis of these lipids, as assayed by in vivo incorporation of (3)H(2)O, was substantial, indicating turnover of 0.4% and 0.7% of total brain cerebroside and cholesterol, respectively, each day. We also studied mice exposed to a diet containing 0.2% of the copper chelator, cuprizone. After 6 weeks 20%, and by 12 weeks, over 30% of brain cerebroside was gone. Demyelination was accompanied by down-regulation of mRNA expression for enzymes controlling myelin lipid synthesis (ceramide galactosyl transferase for cerebroside; hydroxymethylglutaryl-CoA reductase for cholesterol), and for myelin basic protein. Synthesis of myelin lipids was also greatly depressed. The 20% cerebroside deficit consequent to 6 weeks of cuprizone exposure was restored 6 weeks after return to a control diet. During remyelination, expression of myelin-related mRNA species, as well as cerebroside and cholesterol synthesis were restored to normal. However, in contrast to the steady state metabolic turnover in the control situation, all the cerebroside and cholesterol made were accumulated. To the extent that accumulating cerebroside is targeted for eventual inclusion in myelin (discussed) the rate of its synthesis is proportional to remyelination. With our assay, in vivo rates of cerebroside synthesis can be determined for a time window of the order of hours. This offers greater temporal resolution and accuracy relative to classical methods assaying accumulation of myelin components at time intervals of several days. We propose this experimental design, and the reproducible cuprizone model, as appropriate for studies of how to promote remyelination.

Invasion and persistent intracellular colonization of erythrocytes. A unique parasitic strategy of the emerging pathogen Bartonella.

The expanding genus Bartonella includes zoonotic and human-specific pathogens that can cause a wide range of clinical manifestations. A productive infection allowing bacterial transmission by blood-sucking arthropods is marked by an intraerythrocytic bacteremia that occurs exclusively in specific human or animal reservoir hosts. Incidental human infection by animal-adapted bartonellae can cause disease without evidence for erythrocyte parasitism. A better understanding of the intraerythrocytic lifestyle of bartonellae may permit the design of strategies to control the reservoir and transmittable stages of these emerging pathogens. We have dissected the process of Bartonella erythrocyte parasitism in experimentally infected animals using a novel approach for tracking blood infections based on flow cytometric quantification of green fluorescent protein-expressing bacteria during their interaction with in vivo-biotinylated erythrocytes. Bacteremia onset occurs several days after inoculation by a synchronous wave of bacterial invasion into mature erythrocytes. Intracellular bacteria replicate until reaching a stagnant number, which is sustained for the remaining life span of the infected erythrocyte. The initial wave of erythrocyte infection is followed by reinfection waves occurring at intervals of several days. Our findings unravel a unique bacterial persistence strategy adapted to a nonhemolytic intracellular colonization of erythrocytes that preserves the pathogen for efficient transmission by blood-sucking arthropods.

Zonisamide‐Related Confusional State with Prolonged Diffuse Slow‐Wave Bursts: A Case Report.

Purpose: Zonisamide (ZNS; I,2‐benzisoxazolc‐3‐methane‐ sulfonamide) may be associated with schizophrenia‐like psychosis, hyperkinesia, or mania. However, no reports have noted a ZNS‐induced confusional state associated with worsening of electroencephalogruphic (EEG)abnormalities. We report a patient receiving a therapeutic dose of ZNS who developed diverse cognitive and behavioral disorders, including clouding of consciousness, that disappeared after discontinuation of ZNS. The EEG, which showed continuous diffuse slow‐wave bursts, markedly but temporarily improved with intravenous diazepam administration. Case Reporr: A 24‐year‐old woman with an 8‐year history oftemporal lobe epilepsy was admitted to our hospital because of generalized tonic‐clonic convulsions (GTC) due to noncompliance. Her interictal EEG showed focal 6‐Hz spike‐wave complexes independently over the left and right temporal region. Magnetic resonance imaging showed normal appearance of the brain. We instituted 500 mg of ZNS and 600 mg of CBZ per day. She showed normal behavior and cognition until hospital day 4, when psychomotor retardation and emotional instability appeared. She could not perform subtraction or recall a 5‐digit number. Her EEG intermittently revealed frontally dominant diffuse 2 to 4‐Hz high voltage slow‐wave bursts lasting &lt;20 minutes. The slow‐wave bursts followed a sudden onset of bilateral synchrony. When 20 mg of diazepam was administered intravenously, the slow wave bursts mark‐ edly but temporarily improved. Although PHT was added, her confu‐ sional state and EEG patterns did not improve. Serum ZNS, CBZ, and PHT concentrations were 23.3 kg/mL, 4.3 yg/mL, and 7.8 pg/mL, respectively. On the 13th hospital day, ZNS administration was discontinued. By day 15 she had fully recovered and the EEG showed no diffuse slow‐wave bursts. She remained partially amnesic for the events after admission. Conclusions: Because some patients with complex partial seizure (CPS) may develop a psychotic state after a lucid interval of several days following GTC, the cognitive disorder that our patient developed might similarly have been associated with GTC. However, because postictal psychosis typically is not associated with slow‐wave bursts in the EEG, a different explanation is required in the present case. Other case reports have documented prolonged confusion followed GTC due to nonconvulsive status epilepticus (NCSE). However, all of these cases showed NCSE immediately after GTC without a lucid interval. Therefore, we concluded that the patients confusional state most likely was not caused by GTC but instead was related to ZNS administration. Because the serum ZNS concentration did not reach a toxic level, any adverse effects apparently arose at a therapeutic ZNS dose. The patients EEG showed prolonged diffuse slow‐wave bursts con‐ sistent with either toxic encephalopathy or NCSE, the latter being strongly favored by the observation that intravenous diazepam markedly improved the EEG. The diazepam effect was only temporary because, while intravenous diazepam is short‐acting, significant ZNS levels and activity remained in the patients brain. We can hypothesize 2 possib es as to relationships between ZNS and NCSE in this patient: ZNS exacerbating her usual CPS to result in NCSE; and ZNS inducing generalized NCSE unrelated to her usual seizures. The patient's EEG during NCSE, however, differed from typical ictal discharges of CPS in showing regional epileptic discharges or secondary bilateral synchrony. Some cases with generalized NCSE may show diffuse slow‐wave activity resembling that in the present case. Consequently, we could not exclude the possibility that ZNS induced generalized NCSE rather than being related to her usual seizures. Interestingly, it has been reported that tiagabine also may induce generalized NCSE in patients with localization‐related epilepsies.

Crab larval-release rhythms

The same claim, worded differently, is made on the next page-clearly these authors meant what they said: they think the rhythms of these animals are not controlled by an internal clock. It is difficult to imagine how such a misunderstanding could arise: fiddler crabs and Carcinus are the classic organisms used in marine chronobiology studies. The first description of a clock-controlled tidal rhythm was done on a fiddler crab (Bennett e t al. 1957) and the animal has continued to be studied to the present day. Scores of papers on the rhythmicity of this crab, emanating from several labs, have been published (see the 34 yr summary of this work by Palmer 1991). The first study of the internal-clock control of Carcinus maenas rhythms was performed in 1958 (Naylor), and there are at least 50 more papers that have appeared since then from Naylor's lab and several others. The first study of the tidal rhythm of the fish Lipophrypho11s was done in 1965 (Gibson), and recently a nice series of papers (culminating in 1991) on the animal's rhythms have been published by Northcott, Gibson & Morgan; a review of the L. pholis rhythm, and the rhythmicity of other intertidal fishes, was published by Gibson (1992). There cannot be the slightest doubt in the minds of marine chronobiologists (other than Saigusa & Kawagoye) that the tide-associated rhythms of these 3 intertidal animals (and a great many others, see Palmer 1995) are under the control of internal living clocks. Further on in their paper, Saigusa & Kawagoye state that their results 'suggests [that] a light-response mechanism [is] involved even in the circatidal rhythm of intertidal animals' (p 92-93). This assertion is repeated again on p 94: 'This indicates that the 24-h LD cycle functions as the zeitgeber of the circatidal rhythm of Hemigrapsus sanguineus.' This claim creates a problem in my mind. Certainly (to give a n extreme example) one would not expect that the attendance of church each Sunday morning would set the phase of our second-to-second heart-beat rhythm. It is equally illogical to accept a conclusion that the 24-h day-night cycle would set the phase or entrain a n overt 12.4-h organismic tidal rhythm. If it did, the rhythm would no longer match the tides; it would become 24 h in length and lose the survival value once offered by a rhythm. Those 2 comments out of the way, I will turn directly to the rhythm itself. Larvae release in this species is a one-time event, i.e. each individual sheds all its larvae in one ca 6-h interval. This type of behavior is referred to in chronobiological literature a s a 'gated response', meaning it takes place only when a 'gate' is opened to allow the event. When a batch of crabs is collected and brought into the laboratory, they do not all release their offspring on the same day; instead, individuals release at different times over a n interval of several days. And when the response of an entire population, maintained in either a light-dark cycle or constant dim illumination, is plotted it is seen that individual releases occur roughly 25 h later each day. Taking the data at face value, the most obvious interpretation of the population-as-a-whole display is that it is a circa-