Numerical Simulation of Supraglacial Debris Mobility: Implications for Ablation and Landform Genesis

Supraglacial debris does not remain fixed atop ablating ice, but can move across the ice surface as supraglacial topography evolves. This active debris movement (distinct from passive movement due to underlying ice motion) affects landform genesis as well as the rate and spatial distribution of ablation. While observations of debris transport across evolving supraglacial topography are abundant, models of these coupled processes over timescales of decades and longer are few. Here I adapt a numerical model of coupled ablation and downslope debris transport to simulate the evolution of an idealized debris-covered glacier on the timescale of complete de-icing. The model includes ablation that depends on supraglacial debris thickness and a hillslope-scale debris transport function that scales non-linearly with slope angle. Ice thickness and debris distribution evolve with model time, allowing complete simulation of de-icing and landform construction in an idealized glacier test-section. The model produces supraglacial relief that leads to topographic inversions consistent with conceptual models of hummocky landform genesis. Model results indicate that the relief of the glacier surface and postglacial hummocks depend on the relationship between characteristic timescales for ablation and debris transport, which is defined as an index of debris mobility. When debris mobility is high, topographic inversions are rapid and supraglacial and postglacial relief are subdued. When debris mobility is low, more pronounced supraglacial relief is produced, but postglacial relief remains subdued. An intermediate mobility appears to optimize both postglacial relief and the rate of de-icingcompared with both highly-mobile and immobile debris. This enhancement of de-icing due to debris mobility could contribute to the observed anomalous rates of ablation in some debris-covered glaciers.

Calibrating SoilGen2 for interglacial soil evolution in the Chinese Loess Plateau considering soil parameters, and the effect of uncertain forcings’

<p>To better understand interglacial paleosol formation by quantifying the paleosol formation processes on the Chinese Loess Plateau (CLP), we need a soil genesis model calibrated for long timescales.  Here, we calibrate a process-based soil genesis model, SoilGen2, by confronting simulated and measured soil properties for interglacial soils formed in the CLP for various parameter settings. After the calibration of the intrinsic soil process parameters, the effect of uncertainty of external forcings (e.g. dust deposition) on calibration results was assessed.</p><p>This calibration comprises three major soil process formulations, represented by various process parameters. Sequentially : [1]. decalcification by tuning (i) the dissolution constant of calcite (ii) the interception evaporation fraction [2]. clay migration by tuning (iii) the volume of clay in-contact with macropores (iv) the filter coefficient (v) physical weathering (vi) the ectorganic layer thickness [3]. soil organic carbon by tuning the decay rates of (vii) humus and (viii) resistant plant material, and (ix) the ratio of ectorganic/endorganic litter (natural vegetations) (x) the ratio of carbon mineralized (CO<sub>2</sub>) over that still in the food web (biomass and humus) during decomposition. The order of the tuned parameters was based on sensitivity analyses on parameters for modelling (de-)calcification and clay migration done for West European leaching climates, and on C-cycling parameters done for both West European and Chinese circumstances. These parameters, [1 and 3] and [2] were successfully calibrated to the Holocene and the Marine Isotope Stage (MIS) 13 climate evolution of the CLP, respectively. After calibration, soil properties show a strong response to 10 reconstructed dust deposition scenarios reflecting the propagation of uncertainty in dust deposition.</p><p>Our results emphasize the equal importance of calibrating soil process parameters and defining correct external forcings in the future use of soil models. Nevertheless, this calibrated model permits interglacial soil simulation in the CLP over long timescales.</p>

Simulation of Bay-Shaped Shorelines after the Construction of Large-Scale Structures by Using a Parabolic Bay Shape Equation

Among the various causes of coastal erosion, the installation of offshore breakwaters is considered the main cause that influences the most serious changes in shorelines. However, without a proper means for predicting such terrain changes, countries and regions continue to suffer from the aftermath of development projects on coastal land. It has been confirmed that the parabolic bay shape equation (PBSE) can accurately predict shoreline changes under the wave climate diffracted as a result of such development projects. This study developed a shoreline change model that has enhanced the previous shoreline change models by applying PBSE to shoreline changes into bay-shaped features. As an analytical comparison with the second term of the GENESIS model, which is an existing and well-known shoreline change model, a similar beach erosion width was obtained for a small beach slope. However, as the beach slope became larger, the result became smaller than that of the GENESIS model. The validity of the model was verified by applying it to satellite images that demonstrated the occurrence of shoreline changes caused by breakwaters for seaports on the eastern coast of Korea; Wonpyeong beach, Yeongrang beach, and Wolcheon beach. As a result, each studied site converged on the static equilibrium planform within several years. Simultaneously, the model enabled the coastal management of the arrangement of seaports to evaluate how the construction of structures causes serious shoreline changes by creating changes to wavefields.

Taf’īl al-Anmāṭ at-Tafā‘uliyyah fī Ta’līm al-Lugah al-‘Arabiyyah Dākhila al-Bī`ah al-Iṣṭinā’iyyah ‘alā Ḍau’i an-NaẒariyyah al-Ijtimā‘iyyah aṡ- Ṡaqafiyyah li Vygotsky

The interaction patterns of Arabic learning can be realized in an artificial environment based on Vygotsky's socio-cultural theory. This research aims; 1. To know the interaction patterns of learning Arabic in an artificial environment. 2. To know how to activate the interaction patterns of learning Arabic in an artificial environment based on Vygotsky's socio-cultural theory. This research is a qualitative analysis descriptive study with a symbolic interactional approach. The data collected by using observation, interviews and documentation. The results of data analysed by using the Miles and Huberman analysis methods. For validating the data used triangulation method. This study finds out that, 1. The pattern of Arabic learning interaction; a. Interaction between teachers students. b. Interaction between teachers groups of students, c. Interaction between teacher groups student groups. 2. There are important thing in activating the interaction pattern; a. Mediated learning. b. Ensure the regulation in children by using scaffolding techniques in zone proximal development of student (ZPD). c. Apply the micro genesis model by providing collaborative learning. d. Watch for and supervise the use of children's "inner speech" and "private speech" considering their level of cognition and age. e. Using an active system in Arabic learning.

Reciprocal Induction of MDM2 and MYCN in Neural and Neuroendocrine Cancers

MYC family oncoproteins MYC, MYCN, and MYCL are deregulated in diverse cancers and via diverse mechanisms. Recent studies established a novel form of MYCN regulation in MYCN-overexpressing retinoblastoma and neuroblastoma cells in which the MDM2 oncoprotein promotes MYCN translation and MYCN-dependent proliferation via a p53-independent mechanism. However, it is unclear if MDM2 also promotes expression of other MYC family members and has similar effects in other cancers. Conversely, MYCN has been shown to induce MDM2 expression in neuroblastoma cells, yet it is unclear if MYC shares this ability, if MYC family proteins upregulate MDM2 in other malignancies, and if this regulation occurs during tumorigenesis as well as in cancer cell lines. Here, we report that intrinsically high MDM2 expression is required for high-level expression of MYCN, but not for expression of MYC, in retinoblastoma, neuroblastoma, small cell lung cancer, and medulloblastoma cells. Conversely, ectopic overexpression of MYC as well as MYCN induced high-level MDM2 expression and gave rise to rapidly proliferating and MDM2-dependent cone-precursor-derived masses in a cultured retinoblastoma genesis model. These findings reveal a highly specific collaboration between the MDM2 and MYCN oncoproteins and demonstrate the origin of their oncogenic positive feedback circuit within a normal neuronal tissue.

On a model for population with age structure

In this paper we study a linear continuous model describing age structure into a dynamics of one sex population, related with the McKendrick model. McKendrick assumes that the female population can be described by a function of two variables, age and time. Using the method of characteristics and Laplace transform, it is possible to find the function representing the number of births in unit time t and the total population size in some particular cases. In the content of some works referring to the behavior of age-structure one sex population is presented the complete model of the Lotka-McKendrick equation given in the system (5) for simple cases. The genesis model is a simple one that works with the Dirac distribution and it is presented in [1]. When the birth modulus is given by the relation (9), we determine the differential-difference equation for the function B(t) which represents the number of births in unit time, given in (3).

PHÂN TÍCH VÀ ĐÁNH GIÁ QUÁ TRÌNH XÓI LỞ VÀ BỒI TỤ Ở KHU VỰC CỬA SÔNG ĐỒNG TRANH - CẦN GIỜ (TP.HCM)

Study site is a part of Can Gio mangrove biosphere reserve in Can Gio district, Ho Chi Minh City. At present, this area is eroded strongly due to the effects of hydrodynamic impact. Based on the field measurements of coastal profile and shoreline changes from 2013 to 2017 and combination of remote sensing method and GENESIS model, the erosion and deposition processes in 5 years are evaluated and analyzed. The results show that the study site keeps eroding over time and trend to continue in the future. Moreover the study also shows that the erosion rate in the northeast monsoon is higher than that in the southwest monsoon. These results are very important in contribution to shoreline change studies.

Measurement of network-based and random meetings in social networks

Social networks are created by the underlying behavior of the actors involved in them. Each actor has interactions with other actors in the network and these interactions decide whether a social relationship should develop between them. Such interactions may occur due to meeting processes such as chance-based meetings or network-based (choice) meetings. Depending upon which of these two types of interactions plays a greater role in creation of links, a social network shall evolve accordingly. This evolution shall result in the social network obtaining a suitable structure and certain unique features. The aim of this work is to determine the relative ratio of the meeting processes that exist between different actors in a social network and their importance in understanding the procedure of network formation. This is achieved by selecting a suitable network genesis model. For this purpose, different models for network genesis are discussed in detail and their differences are highlighted through experimental results. Network genesis models are compared and contrasted with other approaches available in the literature, such as simulation-based models and block models. Performance measures to compare the results of the network genesis models with baselines are statistics of networks recreated using the models. The socially generated networks studied here belong to various domains like e- commerce, electoral processes, social networking websites, peer to peer file-sharing websites, and Internet graphs. The insights obtained after analyzing these datasets by network genesis models are used for prescribing measures that could ensure continuous growth of these social networks and improve the benefits for the actors involved in them.

Hydrogeochemical Characteristics and Genesis Model of Jinjiang and Julong Hot Springs in Changbai Mountain, Northeast China

Changbai Mountain in China has been explored as a potential area for its rich hot springs including the Jinjiang and Julong hot spring groups. The hydrogeochemical characteristics and conceptual genesis models of the Jinjiang and Julong hot springs were evaluated by hydrogeochemical analysis, isotope analysis, rock sample analysis, hydrogeochemistry simulation, and geophysical exploration method. The results showed that HCO3− and Na+ were the most abundant anion and cation in the hot springs, and the hydrochemical type was Na-HCO3. And the hot springs are enriched with trace components such as H2SiO3 and Sr. The major gas composition of the Jinjiang hot springs and Julong hot springs were CO2, N2, and CH4, which were derived from the mantle. The chemical compositions were produced by feldspar and pyroxene mineral hydrolysis. The recharge source of the hot springs was atmospheric precipitation and was also influenced by evaporation, and the genetic models for the Jinjiang hot springs and Julong hot springs were as follows: the heat source of both was a magma body and heat was mainly migrated in the form of thermal conduction. The cap rocks were both composed of trachyte of Baitoushan formation, basalt of Junjianshan formation, and rhyolitic pyroclastic rocks of Changbai formation. The geothermal reservoir of both hot springs was a fracture zone with the lithology of volcanic breccia, sand, and gravel and volcanic breccia and marble, respectively.