Changes in energy allocation by the predator Nephelopsis obscura exposed to differences in prey availability

1997 ◽  
Vol 75 (4) ◽  
pp. 606-612 ◽  
Author(s):  
D. E. C. Smith ◽  
Ronald W. Davies
Keyword(s):  
Prey Availability ◽  
Low Frequency ◽  
Somatic Growth ◽  
Treatment Temperature ◽  
Medium Frequency ◽  
Reproductive Growth ◽  
Mucus Production ◽  
Nephelopsis Obscura ◽  
Growth Energy ◽  
And Storage

Acquisition of energy and its allocation to components of bioenergetic balance were measured throughout the life cycle in three groups of Nephelopsis obscura fed one (low frequency), two (medium frequency), or three (high frequency) ad libitum meals each week at 15 and 20 °C. As feeding frequency increased, the total amounts of energy ingested, faeces plus mucus produced, somatic and reproductive growth, energy storage (total lipids), and respiration all increased. The proportion of ingested energy allocated to somatic and reproductive growth was highest for the medium-frequency and lowest for the low-frequency feeding treatment. Temperature had no effect on ingestion or faeces plus mucus production, but the respiration rate was higher and the growth rate lower at 20 than at 15 °C. The proportions of ingested energy allocated to growth and storage were the same in the high- and medium-frequency feeding treatments at both temperatures. In the low-frequency feeding treatment, the proportion of energy allocated to storage was higher at 15 °C, but proportionally more energy was allocated to somatic growth and less to reproductive growth or lipid storage at 20 °C. In the high- and medium-frequency feeding treatments, the relative amount of energy allocated to storage was constant, i.e., the ratio of reserves to structural tissues was the same, at both temperatures.

Development of a Low Frequency Electric Field Probe Integrating Data Acquisition and Storage

2020 ◽  
Vol E103.C (8) ◽  
pp. 345-352
Author(s):  
Zhongyuan ZHOU ◽  
Mingjie SHENG ◽  
Peng LI ◽  
Peng HU ◽  
Qi ZHOU
Keyword(s):  
Electric Field ◽  
Data Acquisition ◽  
Low Frequency ◽  
Frequency Electric Field ◽  
Electric Field Probe ◽  
And Storage

How word frequency affects morphological processing in monolinguals and bilinguals

2003 ◽  
Vol 6 (3) ◽  
pp. 213-225 ◽  
Author(s):  
MINNA LEHTONEN ◽  
MATTI LAINE
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Morphological Processing ◽  
Decision Task ◽  
Frequency Range ◽  
Medium Frequency ◽  
Word Forms ◽  
Full Form ◽  
Differential Pattern ◽  
Complex Words

The present study investigated processing of morphologically complex words in three different frequency ranges in monolingual Finnish speakers and Finnish-Swedish bilinguals. By employing a visual lexical decision task, we found a differential pattern of results in monolinguals vs. bilinguals. Monolingual Finns seemed to process low frequency and medium frequency inflected Finnish nouns mostly by morpheme-based recognition but high frequency inflected nouns through full-form representations. In contrast, bilinguals demonstrated a processing delay for all inflections throughout the whole frequency range, suggesting decomposition for all inflected targets. This may reflect different amounts of exposure to the word forms in the two groups. Inflected word forms that are encountered very frequently will acquire full-form representations, which saves processing time. However, with the lower rates of exposure, which characterize bilingual individuals, full-form representations do not start to develop.

scholarly journals RADIOAUTOGRAPHIC ANALYSIS OF THE SECRETORY PROCESS IN THE PAROTID ACINAR CELL OF THE RABBIT

1972 ◽  
Vol 53 (2) ◽  
pp. 290-311 ◽  
Author(s):  
J. David Castle ◽  
James D. Jamieson ◽  
George E. Palade
Keyword(s):  
Intracellular Transport ◽  
Secretory Granules ◽  
Close Association ◽  
Low Frequency ◽  
Secretory Process ◽  
Secretory Proteins ◽  
Surgical Removal ◽  
Storage Granules ◽  
And Storage

Intracellular transport of secretory proteins has been studied in the parotid to examine this process in an exocrine gland other than the pancreas and to explore a possible source of less degraded membranes than obtainable from the latter gland. Rabbit parotids were chosen on the basis of size (2–2.5 g per animal), ease of surgical removal, and amylase concentration. Sites of synthesis, rates of intracellular transport, and sites of packaging and storage of newly synthesized secretory proteins were determined radioautographically by using an in vitro system of dissected lobules capable of linear amino acid incorporation for 10 hr with satisfactory preservation of cellular fine structure. Adequate fixation of the tissue with minimal binding of unincorporated labeled amino acids was obtained by using 10% formaldehyde-0.175 M phosphate buffer (pH 7.2) as primary fixative. Pulse labeling with leucine-3H, followed by a chase incubation, showed that the label is initially located (chase: 1–6 min) over the rough endoplasmic reticulum (RER) and subsequently moves as a wave through the Golgi complex (chase: 16–36 min), condensing vacuoles (chase: 36–56 min), immature granules (chase: 56–116 min), and finally mature storage granules (chase: 116–356 min). Distinguishing features of the parotid transport apparatus are: low frequency of RER-Golgi transitional elements, close association of condensing vacuoles with the exit side of Golgi stacks, and recognizable immature secretory granules. Intracelular processing of secretory proteins is similar to that already found in the pancreas, except that the rate is slower and the storage is more prolonged.

Inversion of low to medium frequency velocities and densities from AVO data using invertible neural networks

Geophysics ◽  
2022 ◽  
pp. 1-44
Author(s):  
Yuhang Sun ◽  
Yang Liu ◽  
Mi Zhang ◽  
Haoran Zhang
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Latent Variables ◽  
Low Frequency ◽  
Inversion Method ◽  
Elastic Parameters ◽  
Medium Frequency ◽  
Uniqueness Of Solutions ◽  
Avo Inversion ◽  
Training Samples

AVO (amplitude variation with offset) inversion and neural networks are widely used to invert elastic parameters. With more constraints from well log data, neural network-based inversion may estimate elastic parameters with greater precision and resolution than traditional AVO inversion, however, neural network approaches necessitate a massive number of reliable training samples. Furthermore, because the lack of low-frequency information in seismic gathers leads to multiple solutions of the inverse problem, both inversions rely heavily on proper low-frequency initial models. To mitigate the dependence of inversions on accurate training samples and initial models, we propose solving inverse problems with the recently developed invertible neural networks (INNs). Unlike conventional neural networks, which address the ambiguous inverse issues directly, INNs learn definite forward modeling and use additional latent variables to increase the uniqueness of solutions. Motivated by the newly developed neural networks, we propose an INN-based AVO inversion method, which can reliably invert low to medium frequency velocities and densities with randomly generated easy-to-access datasets rather than trustworthy training samples or well-prepared initial models. Tests on synthetic and field data show that our method is feasible, anti-noise capable, and practicable.

scholarly journals Motoneuron firing patterns underlying fast oscillations in phrenic nerve discharge in the rat

2012 ◽  
Vol 108 (8) ◽  
pp. 2134-2143 ◽  
Author(s):  
Vitaliy Marchenko ◽  
Michael G. Z. Ghali ◽  
Robert F. Rogers
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Medium Frequency ◽  
Adult Rats ◽  
Time Frequency ◽  
High Frequency Oscillations ◽  
Novel Method ◽  
Frequency Coherence ◽  
Fast Oscillations ◽  
First Time

Fast oscillations are ubiquitous throughout the mammalian central nervous system and are especially prominent in respiratory motor outputs, including the phrenic nerves (PhNs). Some investigators have argued for an epiphenomenological basis for PhN high-frequency oscillations because phrenic motoneurons (PhMNs) firing at these same frequencies have never been recorded, although their existence has never been tested systematically. Experiments were performed on 18 paralyzed, unanesthetized, decerebrate adult rats in which whole PhN and individual PhMN activity were recorded. A novel method for evaluating unit-nerve time-frequency coherence was applied to PhMN and PhN recordings. PhMNs were classified according to their maximal firing rate as high, medium, and low frequency, corresponding to the analogous bands in PhN spectra. For the first time, we report the existence of PhMNs firing at rates corresponding to high-frequency oscillations during eupneic motor output. The majority of PhMNs fired only during inspiration, but a small subpopulation possessed tonic activity throughout all phases of respiration. Significant time-varying PhMN-PhN coherence was observed for all PhMN classes. High-frequency, early-recruited units had significantly more consistent onset times than low-frequency, early/middle-recruited and medium-frequency, middle/late-recruited PhMNs. High- and medium-frequency PhMNs had significantly more consistent offset times than low-frequency units. This suggests that startup and termination of PhMNs with higher firing rates are more precisely controlled, which may contribute to the greater PhMN-PhN coherence at the beginning and end of inspiration. Our findings provide evidence that near-synchronous discharge of PhMNs firing at high rates may underlie fast oscillations in PhN discharge.

scholarly journals Six Temperature Proxies of Scots Pine from the Interior of Northern Fennoscandia Combined in Three Frequency Ranges

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Markus Lindholm ◽  
Maxim G. Ogurtsov ◽  
Risto Jalkanen ◽  
Björn E. Gunnarson ◽  
Tarmo Aalto
Keyword(s):  
Scots Pine ◽  
Model Performance ◽  
Low Frequency ◽  
Atlantic Multidecadal Oscillation ◽  
Frequency Component ◽  
Medium Frequency ◽  
Growth Variability ◽  
Northern Fennoscandia ◽  
Target Period ◽  
Climate Proxies

Six chronologies based on the growth of Scots pine from the inland of northern Fennoscandia were built to separately enhance low, medium, and higher frequencies in growth variability in 1000–2002. Several periodicities of growth were found in common in these data. Five of the low-frequency series have a significant oscillatory mode at 200–250 years of cycle length. Most series also have strong multidecadal scale variability and significant peaks at 33, 67, or 83–125 years. Reconstruction models for mean July and June–August as well as three longer period temperatures were built and compared using stringent verification statistics. We describe main differences in model performance (R2 = 0.53–0.62) between individual proxies as well as their various averages depending on provenance and proxy type, length of target period, and frequency range. A separate medium-frequency chronology (a proxy for June–August temperatures) is presented, which is closely similar in amplitude and duration to the last two cycles of the Atlantic multidecadal oscillation (AMO). The good synchrony between these two series is only hampered by a 10-year difference in timing. Recognizing a strong medium-frequency component in Fennoscandian climate proxies helps to explain part of the uncertainties in their 20th century trends.

scholarly journals Training to Detect Phishing Emails: Effects of the Frequency of Experienced Phishing Emails

2019 ◽  
Vol 63 (1) ◽  
pp. 453-457
Author(s):  
Kuldeep Singh ◽  
Palvi Aggarwal ◽  
Prashanth Rajivan ◽  
Cleotilde Gonzalez
Keyword(s):  
False Alarm ◽  
False Alarm Rate ◽  
High Frequency ◽  
Low Frequency ◽  
Response Criterion ◽  
Training Phase ◽  
Medium Frequency ◽  
Hit Rate ◽  
Hit Rates ◽  
Training Protocols

We studied people’s success on the detection of phishing emails after they were trained under one of three phishing frequency conditions, where the proportion of the phishing emails during training varied as: low frequency (25% phishing emails), medium frequency (50% phishing emails) and high frequency (75% phishing emails). Individual base susceptibility to phishing emails was measured in a pre-training phase in which 20% of the emails were phishing; this performance was then compared to a post-training phase in which participants aimed at detecting new rare phishing emails (20% were phishing emails). The Hit rates, False Alarm rates, sensitivities and response criterion were analyzed. Results revealed that participants receiving higher frequency of phishing emails had a higher hit rate but also higher false alarm rate at detecting phishing emails at post-training compared to participants encountering lower frequency levels during training. These results have implications for designing new training protocols for improving detection of phishing emails.

Rheology, morphology and mechanical properties of LLDPE/PS blends catalyzed by combined Lewis acids

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Yan-Long Liu ◽  
Li-Gang Yin ◽  
Zhuo Ke ◽  
Qiang Shi ◽  
Jing-Hua Yin
Keyword(s):  
Mechanical Properties ◽  
Storage Modulus ◽  
Lewis Acids ◽  
Low Frequency ◽  
Complex Viscosity ◽  
Reactive Blending ◽  
Izod Impact ◽  
Rheological Experiments ◽  
And Storage

AbstractThe rheological, morphological and mechanical properties of LLDPE/PS blends with a combined catalyst, Me3SiCl and InCl3·4H2O, were studied in this work. The higher complex viscosity and storage modulus at low frequency were ascribed to the presence of graft copolymers, which were in situ formed during the mixing process. From the rheological experiments, the complex viscosity and storage modulus of reactive blends were higher than the physical blends. The dispersion of LLDPE particles of reactive blending becomes finer than that of physical blends, consistent with the rheological results. As a result of increased compatibility between LLDPE/PS, the mechanical properties of reactive blends show much higher tensile and Izod impact strength than those of physical blends.

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