Low Initial Growth Research Articles

Predicting autism traits from baby wellness records: A machine learning approach.

Timely identification of autism spectrum conditions is a necessity to enable children to receive the most benefit from early interventions. Emerging technological advancements provide avenues for detecting subtle, early indicators of autism from routinely collected health information. This study tested a model that provides a likelihood score for autism diagnosis from baby wellness visit records collected during the first 2 years of life. It included records of 591,989 non-autistic children and 12,846 children with autism. The model identified two-thirds of the autism spectrum condition group (boys 63% and girls 66%). Sex-specific models had several predictive features in common. These included language development, fine motor skills, and social milestones from visits at 12-24 months, mother's age, and lower initial growth but higher last growth measurements. Parental concerns about development or hearing impairment were other predictors. The models differed in other growth measurements and birth parameters. These models can support the detection of early signs of autism in girls and boys by using information routinely recorded during the first 2 years of life.

Dendroecological analysis of the remote endemic Nothomyrcia fernandeziana forests of Robinson Crusoe Island in the Southeast Pacific

Juan Fernández Archipelago National Park is located in the Southeast Pacific Ocean ∼670 km off the coast of Chile. Composed by three islands, encompasses an ecosystem with 208 native plant species of which 64% are endemic. Robinson Crusoe Island (RCI) is the largest and the only with a permanent human population. Among the tree species of RCI, Nothomyrcia fernandeziana is the most abundant and dominant forming part of this fragile forest ecosystem. Despite this, there is very little information regarding its autoecology and conservation. Therefore, the objective of this work was to determine the radial growth patterns of N. fernandeziana and its longevity using dendrochronological methods. For this purpose, cross sections of trees blown down by wind were collected in conjunction with park rangers from five different sites and analyzed using tree-ring methods. Our results confirm that N. fernandeziana is a shade-tolerant species capable of maintaining extremely low initial growth rates under the canopy for several decades. Individual growth series were found to respond rapidly to changes in environmental conditions, revealed by abrupt positive and negative changes in their annual growth. Our data indicate a longevity of up to 450 years, with one N. fernandeziana individual established in the mid XVII century before the arrival of humans to the pristine island ecosystem. The results of this study are essential to strengthen RCI conservation plans considering restoration actions based on the autoecology of this rare endemic tree species, and the control of exotic invasive species that presently threatens the RCI forests ecosystems.

Modeling the effect of gut microbiome on therapeutic efficacy of immune checkpoint inhibitors against cancer

Immune checkpoint inhibitors have been shown to be highly successful against some solid metastatic malignancies, but only for a subset of patients who show durable clinical responses. The overall patient response rate is limited due to the interpatient heterogeneity. Preclinical and clinical studies have recently shown that the therapeutic responses can be improved through the modulation of gut microbiome. However, the underlying mechanisms are not fully understood. In this paper, we explored the effect of favorable and unfavorable gut bacteria on the therapeutic efficacy of anti-PD-1 against cancer by modeling the tumor-immune-gut microbiome interactions, and further examined the predictive markers of responders and non-responders to anti-PD-1. The dynamics of the gut bacteria was fitted to the clinical data of melanoma patients, and virtual patients data were generated based on the clinical patient survival data. Our simulation results show that low initial growth rate and low level of favorable bacteria at the initiation of anti-PD-1 therapy are predictive of non-responders, while high level of favorable bacteria at the initiation of anti-PD-1 therapy is predictive of responders. Simulation results also confirmed that it is possible to promote patients’ response rate to anti-PD-1 by manipulating the gut bacteria composition of non-responders, whereby achieving long-term progression-free survival.

How the earnings growth of US immigrants was underestimated

Two radically different descriptions of immigrant earnings trajectories in the USA have emerged. One asserts that immigrant men, following the 1965 Immigration and Nationality Act, have low initial earnings and high earnings growth. Another asserts that the post-1965 immigrants have low initial earnings and low earnings growth. We describe the methodological issues that create this divide and show that low earnings growth becomes high earnings growth when immigrants are followed from their initial years in the USA; earnings growth is allowed to vary with entry earnings; and—when following cohorts instead of individuals—sample restrictions commonly used by labor economists are avoided.

Developmental trajectories of empathic concern in infancy and their links to social competence in early childhood.

Empathic concern is an important component of children's social competence. Yet, little is known about the role of the development of concern for others during infancy as a predictor of social competence in early childhood. Israeli infants (N = 165, 50% girls) were observed five times, from 3 to 36 months. Empathic concern was assessed at ages 3-18 months using observations, and four components of social competence were assessed at 36 months using observations and teacher reports. Four groups with distinct developmental trajectories of empathic concern from 3 to 18 months were identified: early-onset (starting high and increasing), low-empathy (starting low with minimal increase), rising (starting low and increasing considerably), and a very small group with a negative slope (decreasing). The first three trajectories differed on aspects of social competence at 36 months. Early-onset children continued to exhibit the highest empathic concern. Both the early-onset and rising groups had greater affective knowledge than the low-empathy group. Moreover, the rising group had better peer relations compared with low-empathy trajectory children. Children who exhibit high levels of empathy early in infancy are likely to show high social competence later on. However, even when initial empathy levels are low, subsequent growth in empathy from 3 to 18 months can occur, with positive consequences for children's social competence at 36 months. Only children with low initial empathic concern and minimal growth across infancy are at increased risk of having poorer socioemotional capabilities in early childhood.

The Study of the Mechanism of Protein Crystallization in Space by Using Microchannel to Simulate Microgravity Environment

Space is expected to be a convection-free, quiescent environment for the production of large-size and high-quality protein crystals. However, the mechanisms by which the diffusion environment in space improves the quality of the protein crystals are not fully understood. The interior of a microfluidic device can be used to simulate a microgravity environment to investigate the protein crystallization mechanism that occurs in space. In the present study, lysozyme crystals were grown in a prototype microchannel device with a height of 50 μm in a glass-polydimethylsiloxane (PDMS)-glass sandwich structure. Comparative experiments were also conducted in a sample pool with a height of 2 mm under the same growth conditions. We compared the crystal morphologies and growth rates of the grown crystals in the two sample pools. The experimental results showed that at very low initial supersaturation, the morphology and growth rates of lysozyme crystals under the simulated microgravity conditions is similar to that on Earth. With increasing initial supersaturation, a convection-free, quiescent environment is better for lysozyme crystal growth. When the initial supersaturation exceeded a threshold, the growth of the lysozyme crystal surface under the simulated microgravity conditions never completely transform from isotropic to anisotropic. The experimental results showed that the convection may have a dual effect on the crystal morphology. Convection can increase the roughness of the crystal surface and promote the transformation of the crystal form from circular to tetragonal during the crystallization process.

Life history constraints explain negative relationship between fish productivity and dissolved organic carbon in lakes.

Resource availability constrains the life history strategies available to organisms and may thereby limit population growth rates and productivity. We used this conceptual framework to explore the mechanisms driving recently reported negative relationships between fish productivity and dissolved organic carbon (DOC) concentrations in lakes. We studied populations of bluegill (Lepomis macrochirus) in a set of lakes with DOC concentrations ranging from 3 to 24 mg/L; previous work has demonstrated that primary and secondary productivity of food webs is negatively related to DOC concentration across this gradient. For each population, we quantified individual growth rate, age at maturity, age‐specific fecundity, maximum age, length‐weight and length‐egg size relationships, and other life history characteristics. We observed a strong negative relationship between maximum size and DOC concentration; for instance, fish reached masses of 150 to 260 g in low‐DOC lakes but <120 g in high‐DOC lakes. Relationships between fecundity and length, and between egg size and length, were constant across the DOC gradient. Because fish in high‐DOC lakes reached smaller sizes but had similar fecundity and egg size at a given size, their total lifetime fecundity was as much as two orders of magnitude lower than fish in low‐DOC lakes. High DOC concentrations appeared to constrain the range of bluegill life history strategies available; populations in high‐DOC lakes always had low initial growth rates and high ages at maturity, whereas populations in low‐DOC showed higher variability in these traits. This was also the case for the intrinsic rates of natural increase of these populations, which were always low at the high end of the DOC gradient. The potentially lower capacity for fish populations in high‐DOC lakes to recover from exploitation has clear implications for the sustainable management of recreational fisheries in the face of considerable spatial heterogeneity and ongoing temporal change in lake DOC concentrations.

Early growth of camu-camu plants with nitrogen fertili- zation through fertirrigation

The objective of this study was to evaluate the effect of different doses of nitrogen (N), applied via fertirrigation, on the initial growth components of the camu-camu plants. It was conducted with the use of a randomized block experimental design with 5 treatments: 0; 40; 80; 120 and 160 kg ha-1 of N, eight replicates and seven plants per experimental parcel. The experiment lasted for a period of 270 days. The diameter of stem (mm) and the height of the plant (cm) were evaluated every 30 days and the number of branches and total length of branches (cm) were evaluated every 90 days. At the end of the experiment, chlorophyll a index, dry mass of the leaves (g), dry mass of the branches (g), dry mass of the roots (g), total dry mass (g), and the Dickson Quality Index (DQI) were evaluated. According to the results, camu-camu plants that did not receive nitrogen fertilization had a lower initial growth and the doses of N significantly influenced all parameters evaluated in the camu-camu plants, including parameters from a linear and a quadratic model. The dose of 123 kg ha-1 of N, applied via fertirrigation, produced better quality camu-camu plants. Furthermore, greater doses caused depressive effects on growth of camu-camu plants in the first year of cultivation in firm ground conditions and the indirect measurement of chlorophyll a index in camu-camu plants was suitable for the assessment of nutritional status in relation to N.

Drivers of Growth in Fast Emerging Economies: A Dynamic Instrumental Quantile Approach

This study complements the scarce literature on growth determinants in fast emerging economies of the BRICS and MINT by assessing the determinants throughout the conditional distributions of the growth rate and real GDP output for the period 2001-2011. An instrumenal variable (IV) quantile regression approach is complemented with Two-Stage-Least Squares and IV Least Absolute Deviations. The instrumentation process is dynamic. The following findings are established. First, while Gross FDI has a negative effect on economic growth, the impact of Net FDI is positive, with a higher magnitude in top quantiles of the distributions. Second, the positive effect of natural resources is more apparent in countries with low initial growth levels. Third, the impact of telecommunications infrastructure is not very significant. Fourth, whereas the incidence of bank credit is positive for GDP growth, it is negative for real GDP output. Fifth, while trade openness is positive in bottom quantiles of GDP growth, but for the highest quantile in real GDP output, it is consistently negative on real GDP output. Sixth, while the incidence of political stability is negative on GDP growth, it is positive on real GDP output, with the negative (positive) effect apparent only in top (bottom) quantiles of GDP growth (real GDP output). Policy implications are discussed.

The debt trap: A two-compartment train wreck… and how to avoid it

We explore sustainable paths out of a debt trap with a highly stylized two-sector differential equations model for the stocks of money in Government and Society. The model fits the data for the U.S. between 1981 and 2012 with a coefficient of correlation of 0.996. The solutions provide detailed “escape conditions” from the debt trap. A primary surplus is required. Then a government can escape its debt trap either through sustained annual monetary outflows from society to the government (taxation) but with a low initial growth rate, or through annual monetary inflows into both sectors (stimulus) with higher initial growth rate. We illustrate the use of our model with simulations which show how five indebted countries can escape their debt trap in 30 (or 70) years.

Effects of Initial GaN Growth Mode on Patterned Sapphire on the Opto-Electrical Characteristics of GaN-Based Light-Emitting Diodes

We have studied the initial growth modes of GaN on patterned sapphire substrate (PSS) with different initial TMGa flow rates. The FWHM of the (102) XRD spectrum of GaN on PSS increased from 470 to 580 arcsec when the initial TMGa flow rate was increased from 80 to 200 sccm. A low TMGa flow rate sufficiently suppresses GaN island growth on the top of the pattern and hence improves GaN crystal quality. The electrical and optical characteristics of GaN-based LEDs on PSS with low initial TMGa were also improved. More than 90% of the GaN LED chips with low initial GaN growth rate can hold the 1-kV machine-mode electrostatic discharge level.

Effect of type of sterile cytoplasm on manifestation of economically valuable traits in sorghum-sudangrass hybrids

A comparative analysis of sorghum-sudangrass hybrids produced on the basis of isonuclear alloplasmic sorghum lines with different sterile cytoplasm types has revealed significant differences between them with respect to economically valuable traits. Hybrids produced with the use of A3 cytoplasm are characterized by low initial growth and narrow leaves; A4 cytoplasm, by more intensive initial growth and high carotene content; and 9E cytoplasm, by a lower green mass yield and wider leaves.

Epitaxial growth of topological insulator Bi 2Se 3 film on Si(111) with atomically sharp interface

Atomically sharp epitaxial growth of Bi 2Se 3 films is achieved on Si(111) substrate with molecular beam epitaxy. Two-step growth process is found to be a key to achieve interfacial-layer-free epitaxial Bi 2Se 3 films on Si substrates. With a single-step high temperature growth, second phase clusters are formed at an early stage. On the other hand, with low temperature growth, the film tends to be disordered even in the absence of a second phase. With a low temperature initial growth followed by a high temperature growth, second-phase-free atomically sharp interface is obtained between Bi 2Se 3 and Si substrate, as verified by reflection high energy electron diffraction (RHEED), transmission electron microscopy (TEM) and X-ray diffraction. The lattice constant of Bi 2Se 3 is observed to relax to its bulk value during the first quintuple layer according to RHEED analysis, implying the absence of strain from the substrate. TEM shows a fully epitaxial structure of Bi 2Se 3 film down to the first quintuple layer without any second phase or an amorphous layer.

Optimization of initial MOVPE growth of non‐polar m‐ and a‐plane GaN on Na flux grown LPE‐GaN substrates

AbstractWe optimized the initial GaN growths of nonpolar m‐ and a‐plane GaN grown on liquid phase epitaxy (LPE‐) GaN substrates. Such nonpolar LPE‐GaN substrates were produced by cutting slices from c‐plane LPE‐GaN bulk single crystals grown by the Na‐flux method. We investigated the qualities of epitaxially grown GaN layers on the LPE‐GaN substrates, with different polishing methods, which are chemical mechanical polishing and plasma dry etch polishing. We found that the crystalline quality of epitaxial GaN on m‐plane GaN is very sensitive to the surface polishing even the minute unevenness in GaN substrate. Our experiments also indicated that a low initial growth rate was necessary to obtain high‐crystalline‐quality epitaxial m‐plane GaN. In contrast, high‐crystalline‐quality a‐plane GaN was obtained even with a high initial growth rate, indicating that the crystalline quality of a‐plane GaN is not sensitive to surface roughness. (© 2011 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Patterns of larval growth and chemical composition in the Amazon River prawn, Macrobrachium amazonicum

The Amazon River prawn, Macrobrachium amazonicum (Heller, 1862), is a target species for regional fisheries in Brazil and a candidate for aquaculture. Under controlled laboratory conditions (29 °C, 10‰), the larval phase of this species shows variability in the morphology and number of successive stages (mostly 9–10, occasionally 8 to > 12). In the most commonly observed developmental pathway (9 stages, taking approximately 20–22 days from hatching to the first juvenile stage), we studied patterns of larval growth in terms of total body length (TL), carapace length (CL), dry mass (W), and elemental composition (carbon, hydrogen, nitrogen; collectively CHN). At hatching, about 12% of late embryonic W, 15–18% of C and H, but only 7% of N were lost, indicating higher losses of lipids and/or carbohydrates than proteins. Significant variability was observed in the initial biomass and elemental composition of newly hatched larvae from 20 different egg batches. This may cause variation in the endotrophic potential of the early stages, as the zoea I of this species is a non-feeding stage, and also the zoea II may still utilize internal energy stores remaining from the egg yolk. Lacking or low larval feeding activity from hatching through stage II coincided with low initial growth. Concomitantly, the proportions of C and H (in % of W) as well as the C:N ratio decreased from hatching through stage IV, indicating a utilization of stored lipids. The percentage of N showed an opposite pattern, reflecting protein synthesis associated with morphogenesis. Size growth showed maximum increments per moult in the late zoeal stages (III–VI), followed by lower increments in the subsequent decapodid stages (VII–IX). This sigmoidal growth pattern may reflect ontogenetic changes in morphometric relationships. Biomass showed exponential patterns of increase from zoeal stage III throughout later larval development and in the first two juvenile stages. Furthermore, patterns of larval growth in M. amazonicum are characterized as linear relationships between larval W in stage n and that in stage n + 1 (Hiatt diagram), between larval size (CL) and biomass (W, C), and between W and either C or N. Using CHN data, we also provide estimates of the protein and lipid contents of larval biomass (ca. 38–46% and 10–12% of W, respectively). High survival, rapid development, and predictable patterns of larval growth support the assumption that M. amazonicum should be a suitable species for production in aquaculture.

Identifying and Predicting Classes of Response to Explicit Phonological Spelling Instruction During Independent Composing

After explicit spelling instruction, low achieving second grade spellers increased the number of correctly spelled words during composing but differed in response trajectories. Class 1 (low initial and slow growth) had the lowest initial performance and improved at a relatively slow rate. Class 2 (high initial and fast growth) started higher than Class 1 but below Class 3 and improved at the fastest rate. Class 3 (highest initial but slow growth) had the highest initial performance but improved at a rate similar to Class 1. Class 3 differed from Classes 1 and 2 on orthographic coding. Classes 1, 2, and 3 differed on rapid automatic naming (RAN letters). Spelling instruction plus supplementary activities to improve orthographic coding in working memory and rapid, automatic coordination of phonological and orthographic codes may facilitate transfer of spelling learned during instruction to applying that spelling knowledge during independent composing.

Optimization and scale-up of CNF production based on intrinsic kinetic data obtained from TEOM

Optimizing the operating parameters for growing carbon nanofibers (CNFs) is an important step toward the large-scale production of CNFs with a high degree of structure control. The present work demonstrates that a tapered-element oscillating microbalance (TEOM) is an excellent tool for the kinetic study of the highly dynamic process of CNF growth. Initial CNF growth rates, deactivation rates, and yields can be studied simultaneously as a function of temperature, pressure, hydrogen partial pressure, or residence time. The kinetic data from TEOM studies are directly implemented to scale up the production of CNF. For a hydrotalcite (HT)-derived Ni catalyst (77 wt% Ni), the highest CNF growth rate was obtained at a temperature of around 580 °C and a hydrogen partial pressure of around 0.1 bar. High temperatures and low partial pressures of hydrogen resulted in a high initial growth rate and deactivation rate, whereas low temperatures and high partial pressures of hydrogen resulted in low initial growth rate and deactivation rate. A carbon capacity (maximum carbon yield) of 50 g/g cat could be achieved at optimized conditions. Growth rates and CNF yields were found to increase with increasing total pressure (0.3–3.8 bar). The mechanisms of CNF growth and deactivation were explored based on kinetic data and DFT calculation studies from the literature. The results obtained from the TEOM studies were verified in a PFR fixed-bed reactor and a horizontally placed fixed-bed reactor similar to a CSTR reactor. The residence time of methane was identified as the most important parameter for scaling up the process. The data on the effect of hydrogen from the TEOM were reproduced, and a successful scale-up of 10,000 times was achieved.

Population Growth in High‐Amenity Rural Areas: Does it Bring Socioeconomic Benefits for Long‐Term Residents?*

OBJECTIVE: A widely noted concern with amenity-driven rural population growth is its potential to yield only low-wage service-sector employment for long-term residents, while raising local costs of living. This research examines change in socioeconomic status during the 1990s for long-term residents of high-amenity, high-growth rural counties in the United States. METHODS: Using longitudinal data from the Panel Study of Income Dynamics, in combination with county-level information, we estimate growth-curve models to examine the extent to which the socioeconomic status of long-term residents is associated with amenity-related in-migration. RESULTS: We find that, on average, residents in high-growth, amenity-rich rural areas have higher income growth over time and higher levels of initial occupational prestige compared to those from other rural areas, but that socioeconomic gains are primarily for individuals with low baseline prestige. CONCLUSIONS: The socioeconomic gains made by long-term residents of high-growth, amenity-rich rural areas associated with net in-migration may be limited to individuals with low initial prestige and growth may be due to low-skill service-sector jobs.

Dehydration-induced alterations in growth and osmotic potential of callus from six tepary bean lines varying in drought resistance

Growth and osmotic potential of calli induced from leaf- and root-derived tissues of six tepary bean lines (Phaseolus acutifolius) varying in drought resistance were assessed in vitro after polyethylene glycol-induced (10%, PEG-10,000) dehydration. Calli of resistant teparies were characterized by low initial osmotic potential (ψs) and relative growth rate (RGR) on medium lacking PEG (−0.30 MPa). However, calli of both resistant and sensitive lines were similar in dry matter percent (DM). Presence of PEG in the medium (−0.58 MPa) elevated DM in all teparies except one resistant line. Both leaf- and root-derived calli of sensitive teparies exhibited osmotic adjustment (OA) but reduced RGR that remained after rehydration in one line. We concluded that preexisting force of low cellular ψs rather than induced OA plays an important role in buffering adverse effects of dehydration and conditioning drought resistance of tepary beans. This information may aid Phaseolus breeders in screening for drought resistance among large number of accessions.

Reduction of Incubation Period by Employing OH-Terminated Si(001) Substrates in the Atomic Layer Deposition of Al2O3

The phenomenon of low initial growth rates in atomic layer deposition (ALD) of various oxides on HF-treated (thus H-terminated) Si(001) substrates, which is termed the incubation effect or incubation period, can be effectively avoided by use of OH-terminated Si(001) substrates. Two ways of preparing OH-terminated Si(001) were devised in this work: one from atomically clean Si(001) and the other from H-terminated Si(001). The effect of reducing the incubation period was confirmed in the ALD process of aluminum oxide (Al2O3) thin films in which trimethylaluminum and water were used as sources of aluminum and oxygen, respectively. The use of OH-terminated Si(001) substrates has another beneficial effect of producing thin films with very smooth surface morphology. We propose the use of OH-terminated Si(001) substrates for growing thin films of many other metal oxides that have shown the incubation period on H-terminated Si(001) substrates.