Light is a key environmental factor that synchronizes all life-stages of fish, from embryo development to sexual maturation. The underwater photo-environment is complex since light characteristics ...(i.e. intensity, photoperiod and spectrum) depend on the absorbance properties of the water column. The aim of this paper is to review the effects of artificial lighting conditions on the performance, development and welfare of some fish larvae of commercial interest. Reviewed results show that larvae were significantly affected by light characteristics. For example, European sea bass and sole larvae achieved the best performance, and showed fastest development and lowest degree of deformity under a light/dark cycle using blue light (half-peak bandwidth
=
435–500
nm), conditions which were the closest to their natural aquatic environment. However, constant light (LL) or constant darkness (DD) was shown to negatively affect normal larval development and resulted in increased malformations and poor survival in most of the studied species. Similar results have been observed in other fish larvae such as Atlantic cod, which performed better under short wavelengths (blue and green). These findings highlight the role of lighting conditions during the early development of fish larvae and should be taken into account for the optimization of rearing protocols in fish hatcheries as juvenile supply is one of the main production bottlenecks.
Abstract Feeding cycles entrain biological rhythms, which enable animals to anticipate feeding times and so maximize food utilization and welfare. In this article, the effect of mealtime was ...investigated in two groups of sea bream ( Sparus aurata ): one group received a single daily meal at random times during the light period (random daytime feeding, RDF), whereas the other group received the meal during the light period but at the same time (scheduled daytime feeding, SDF). All the fish showed diurnal behavior, although the SDF group showed a lower percentage of diurnalism (84.4% vs. 79.5% in RDF and SDF respectively) and developed food anticipatory activity some hours before the mealtime. In addition, the mean daily locomotor activity of the RDF group was significantly higher than that of the SDF group (3132 vs. 2654 counts/day, respectively). Although the mean weight differed between both groups on day 30 (115.7 g and 125.6 g in RDF and SDF respectively), these differences had disappeared by day 60. Plasma cortisol and glucose significantly differed in both groups (cortisol: 71.8 vs. 8.7 ng/ml, glucose: 53.7 vs. 43.8 mg/dl in RDF and SDF, respectively), whereas lactate did not differ significantly. The results obtained suggest that altering the feeding time (scheduled vs. random) affects the behavior and physiology of sea bream, indicating that a single daily feeding cycle (compared to random) is beneficial for fish welfare because they can prepare themselves for the forthcoming feed.
Feeding cycles entrain biological rhythms, which enables animals to anticipate feeding times and so maximizes food utilization. In this article the effect of mealtime on locomotor activity, blood ...glucose, gastric pH and digestive enzymes was studied in two groups of seabream (
Sparus aurata): one group received a single daily meal at random times either during the light or the dark (random feeding, RF), whereas the other group received the meal during the light period every day at the same time (periodic feeding, PF). PF fish showed strong synchronisation of locomotor activity to the light phase (97.9
±
0.2% of their total daily activity during daytime). In addition, the locomotor activity rhythm of PF fish showed a statistically significant daily rhythm (p
<
0.05) for a period of 24
h, whereas RF fish did not display a statistically significant rhythm. Blood glucose levels were higher in RF fish during the 8
h following feeding. Gastric pH showed a postprandial decrease in both groups, but RF fish showed a lower daily average value (4.31
±
0.21 compared with 5.52
±
0.20). Amylase and alkaline protease activity increased some hours before mealtime in PF fish, whereas amylase activity increased 1
h after feeding and alkaline protease showed no statistically significant differences in RF fish. Acid protease activity showed no statistically significant differences in any group. Taken together, these results demonstrate that altering the feeding time affects the physiology and behaviour of seabream, which have the capacity to prepare themselves for a forthcoming meal.
Submicrosecond (0.476 μs per frame with an exposure time of 160 ns) high‐resolution (0.38 nm) time‐resolved spectra of laboratory‐produced lightning‐like electrical discharges have been recorded for ...the first time within the visible spectral range (645–665 nm). The spectra were recorded with the GrAnada LIghtning Ultrafast Spectrograph (GALIUS), a high‐speed imaging spectrograph recently developed for lightning research in the IAA‐CSIC. Unprecedented spectral time dynamics are explored for meter long laboratory electrical discharges produced with a 2.0 MV Marx generator. The maximum electron density and gas temperature measured in a timescale of ≤0.50 μs (160 ns) were, respectively, ≃1018 cm−3 and ≃32,000 K. Overpressure in the lightning‐like plasma channel, black‐body dynamics, and self‐absorption in spectral lines were investigated.
Plain Language Summary
Lightning are extremely rapid and violent atmospheric electricity events taking place inside thunderclouds and between thunderclouds and the ground. Investigation of the fundamental properties of different types of lightning and lightning leaders can help to deepen our understanding on lightning propagation dynamics (stepping) and how lightning can produce high‐energy pulses of X‐ray or pulses of even higher energy (the so‐called terrestrial gamma‐ray flashes). Time‐resolved optical emission spectroscopy is an ideal diagnostic technique to remotely study the fast temporal dynamics of lightning. The fastest spectroscopic techniques used to date were able to achieve microsecond timescales. We present the first study exploring submicrosecond time regimes using the GrAnada LIghtning Ultrafast Spectrograph (GALIUS), a high‐speed imaging spectrograph recently developed for lightning research at the IAA‐CSIC.
Key Points
Submicrosecond time‐resolved spectra of lightning‐like discharges are presented for the first time
Some evidence points to slight non‐LTE conditions right behind the shock front in posttrigger submicrosecond times
Optical thickness goes from thin (pretrigger times) to thick (submicrosecond) and back to thin (few microseconds)
This study investigates how the characteristics (spectrum and photoperiod) of artificial light affect European sea bass eggs and larvae from −
1 to 40 days post-hatching. Fertilised eggs and larvae ...were reared under five different light treatments: 12L:12D red light (LDR; half-peak bandwidth
=
641–718 nm), 12L:12D blue light (LDB; half-peak bandwidth
=
435–500 nm), 12L:12D broad-spectrum white light (LDW; 367
<
λ
<
1057 nm), 24L:0D broad-spectrum white light (LL) and 0L:24D (DD). The results showed that total length at day post-hatching 40 was significantly larger in larvae reared under LDB (15.4
±
0.6 mm) and LL (15.2
±
0.6 mm) than in larvae reared under LDR (11.7
±
0.7 mm). Overall wet weight was highest under LDB (21.6
±
2.02 mgr) and lowest in LDR larvae (13.6
±
1.48 mgr). Yolk sac and oil globule absorption occurred more slowly in LDR and DD larvae, while LDB larvae developed their fin, teeth and swim bladder significantly earlier than the rest of the groups. DD larvae were unable to capture food and mortality was 100% by day post-hatching 18, while LDR larvae did not feed on rotifers, but fed on
Artemia from day post-hatching 16 onwards. The best survival was obtained with the LL treatment, although significantly more problems with swim bladder development and lower jaw malformations were also identified in this group. In summary, these results highlight the key role of the light spectrum and photoperiod for European sea bass larvae, the best performance being achieved under the light conditions that best approached those of their natural aquatic environment (LDB). These findings should be considered when designing rearing protocols for larvae in aquaculture.
Abstract Food availability is far from constant but tends to be cyclic, and fish therefore show a variety of circadian rhythms which can be entrained to feeding time. The aim of this study was to ...investigate the synchronization to mealtimes of behavioral (locomotor activity), metabolic (glucose) and endocrine (cortisol and thyroid hormones) daily rhythms in gilthead seabream. To this end, fish were reared under a 12:12 LD cycle and fed 1% of their body weight once a day either at mid-light (ML) or at mid-dark (MD) of the LD cycle. Fish synchronized their locomotor activity to the phase in which food was delivered, ML and MD fish displaying 86 ± 3% and 81 ± 1% of their total daily activity during daytime and nighttime, respectively. Daily variations of blood glucose were strongly synchronized to feeding time in both experimental groups, peaking 8 h after the meal. A postprandial cortisol peak was observed in both groups. In fish fed at MD the cortisol values were high during the 8 h following feeding, whereas in fish fed at ML cortisol levels returned to basal values within 4 h. In addition, MD fish showed a higher average daily cortisol value (24.75 ± 2.65 ng/ml) than ML fish (10.30 ± 2.18 ng/ml). Feeding time affected the magnitude of daily variations in the thyroid hormones. When the time of feeding was delayed by 12 h, a shift of the same magnitude could be observed in the glucose daily rhythm and a dramatic change in the cortisol levels of the ML-fed group compared with results mentioned above. In summary, gilthead seabream synchronized their locomotor activity to the phase when food was provided and showed different degrees of synchronization of their behavioral, metabolic and endocrine rhythms to feeding time. Since these parameters are used to evaluate stress responses and welfare in seabream, their daily rhythm and synchronization to light and feeding time should be taken into account.
To evaluate whether follow-up of patients with obstructive sleep apnoea (OSA) undergoing CPAP treatment could be performed in primary care (PC) settings.
Non-inferiority, randomised, prospective ...controlled study.
Sleep unit (SU) at the University Hospital and in 8 PC units in Lleida, Spain.
Patients with OSA were randomised to be followed up at the SU or PC units over a 6-month period.
The primary outcome was CPAP compliance at 6 months. The secondary outcomes were Epworth Sleep Scale (ESS) score, EuroQoL, patient satisfaction, body mass index (BMI), blood pressure and cost-effectiveness.
We included 101 patients in PC ((mean±SD) apnoea-hypopnoea index (AHI) 50.8±22.9/h, age 56.2±11 years, 74% male) and 109 in the SU (AHI 51.4±24.4/h, age 55.8±11 years, 77% male)). The CPAP compliance was (mean (95% CI) 4.94 (4.47 to 5.5) vs 5.23 (4.79 to 5.66) h, p=0.18) in PC and SU groups, respectively. In the SU group, there were greater improvements in ESS scores (mean change 1.79, 95% CI +0.05 to +3.53, p=0.04) and patient satisfaction (-1.49, 95% CI -2.22 to -0.76); there was a significant mean difference in BMI between the groups (0.57, 95% CI +0.01 to +1.13, p=0.04). In the PC setting, there was a cost saving of 60%, with similar effectiveness, as well as a decrease in systolic blood pressure (-5.32; 95% CI -10.91 to +0.28, p=0.06).
For patients with OSA, treatment provided in a PC setting did not result in worse CPAP compliance compared with a specialist model and was shown to be a cost-effective alternative.
Clinical Trials NCT01918449.
Abstract The existence of food anticipatory activity (FAA) in animals subjected to daily feeding schedules seems to be mediated by a feeding-entrainable oscillator (FEO). Such an FEO may help in ...anticipating meal time and so optimizing food acquisition and nutrient utilization. In this study we investigated the existence of FAA and whether digestive enzymes, plasma cortisol, hypothalamic NPY and gastrointestinal tract (GIT) and plasma melatonin were entrained by periodic feeding in goldfish. We observed that periodically fed goldfish showed FAA in locomotor activity as well as in amylase and NPY. Alkaline protease and GIT melatonin were higher after feeding, whereas plasma cortisol levels were reduced. Plasma melatonin remained unmodified before and after meal time. These results suggested that scheduled feeding entrained both behavioral and certain physiological patterns in goldfish, FAA being of adaptive value to anticipate a meal and prepare the digestive physiology of fish.
This paper investigates the impact of different thermo- and photo-cycles of distinct wavelengths on
Solea senegalensis larvae from day 1 to 30 post-hatching. In experiment 1, larvae were exposed to ...12
h light:12
h dark (12
L:12D) cycle and (A) constant temperature (20.7
°C), (B) thermocycle of 12
h thermophase: 12
h cryophase, 22.1
°C day: 19.0
°C night (referred to as TC) or (C) 12
h cryophase: 12
h thermophase, 19.2
°C day: 22.0
°C night (referred to as CT). In experiment 2, larvae were kept under constant temperature (20.8
°C) and exposed to (A) continuous light (LL), (B) continuous darkness (DD), and LD 12
L:12D cycles of (C) white light (LD
W), (D) blue light (LD
B) or (E) red light (LD
R). The sole larvae achieved the best performance, and showed fastest development and lowest degree of deformity under natural thermocycle conditions (TC) with a deformity percentage of 31.1% and LD
B cycles with 27.7% of malformation, conditions which were nearest their natural aquatic environment. Larvae reared under TC started eye migration at 9
day post-hatching (DPH), while larvae exposed to CT started eye migration at 11 DPH. In larvae under the LD
B treatment the migration of the eye started earlier than in the other treatments (9 DPH), while larvae reared under LL and DD photoperiods died before metamorphosis. These findings highlight the importance of light and temperature cycles during the early development of
S.
senegalensis larvae, which should be taken into consideration in experimental or rearing protocols.
Clinical spectrum of BICD2 mutations Frasquet, M.; Camacho, A.; Vílchez, R. ...
European journal of neurology,
July 2020, 2020-07-00, 20200701, Letnik:
27, Številka:
7
Journal Article
Recenzirano
Background and purpose
Mutations in the BICD2 gene cause autosomal dominant lower extremity‐predominant spinal muscular atrophy 2A (SMALED2A), a condition that is associated with a specific pattern ...of thigh and calf muscle involvement when studied by magnetic resonance imaging (MRI). Patients may present minor clinical sensory impairment, but objective sensory involvement has yet to be demonstrated.
Methods
We collected clinical data from 11 patients from five different families carrying mutations in BICD2. Genetic diagnosis was achieved using gene panel testing and skin biopsies were taken from two patients to study the epidermal nerve fiber density.
Results
In the studied patients, three new pathogenic mutations were detected as well as the already defined pathogenic p.Ser107Leu mutation. The most frequent clinical picture was characterized by lower‐limb weakness in combination with foot deformities. One patient manifested clinical and electrophysiological sensory impairment, and the epidermal nerve fiber density study of another patient revealed the existence of a small‐fiber neuropathy. Muscle MRI showed a common pattern of fat deposition including selective involvement of gluteus medius and minimus at the pelvic level, the anterior compartment of the thigh and the posterior compartment of the calf, with only mild or no involvement of the intrinsic foot muscles.
Conclusions
We report three new pathogenic mutations in the BICD2 gene. Muscle MRI confirms the existence of a selective pattern of thigh and leg muscle involvement in SMALED2A, providing additional information regarding pelvic and foot muscles. Moreover, our results raise the possibility of sensory involvement in the disease.
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