Re-examination of the Effects of Food Abundance on Jaw Plasticity in Purple Sea Urchins

Morphological plasticity is a critical mechanism that animals use to cope with variations in resource availability. During periods of food scarcity, sea urchins demonstrate an increase in jaw length relative to test diameter. This trait is thought to be reversible and adaptive by yielding an increase in feeding efficiency. We directly test the hypotheses that (1) there are reversible shifts in jaw length to test diameter ratios with food abundance in individual urchins, and (2) these shifts alter feeding efficiency. Purple sea urchins, Strongylocentrotus purpuratus, were collected and placed in either high or low food treatments for 3 months, after which treatments were switched for two additional months between February and September, 2015 in La Jolla, CA (32.8674°N, 117.2530°W). Measurements of jaw length to test diameter ratios were significantly higher in low compared to high food urchins, but this was due to test growth in the high food treatments. Ratios of low food urchins did not change following a switch to high food conditions, indicating that this trait is not reversible within the time frame of this study. Relatively longer jaws were also not correlated with increased feeding efficiency. We argue that jaw length plasticity is not adaptive and is simply a consequence of exposure to high food availability, as both jaw and test growth halt when food is scarce

Enhanced Representative Days and System States Modeling for Energy Storage Investment Analysis

This paper analyzes different models for evaluating investments in Energy Storage Systems (ESS) in power systems with high penetration of Renewable Energy Sources (RES). First of all, two methodologies proposed in the literature are extended to consider ESS investment: a unit commitment model that uses the System States (SS) method of representing time; and another one that uses a representative periods (RP) method. Besides, this paper proposes two new models that improve the previous ones without a significant increase of computation time. The enhanced models are the System States Reduced Frequency Matrix (SS-RFM) model which addresses short-term energy storage more approximately than the SS method to reduce the number of constraints in the problem, and the Representative Periods with Transition Matrix and Cluster Indices (RP-TM&CI) model which guarantees some continuity between representative periods, e.g. days, and introduces long-term storage into a model originally designed only for the short term. All these models are compared using an hourly unit commitment model as benchmark. While both system state models provide an excellent representation of long-term storage, their representation of short-term storage is frequently unrealistic. The RP-TM&CI model, on the other hand, succeeds in approximating both short- and long-term storage, which leads to almost 10 times lower error in storage investment results in comparison to the other models analyzed

Housewifization

Housewifization by Maya Weisinge

Book Review Of Orang-orang Proyek Written By Ahmad Tohari

Di Indonesia korupsi bukan menjadi masalah yang baru bagi pemerintah. Korupsi mulai terjadi di Indonesia pada masa orde lama tetapi masih sedikit para birokrasi yang melakukan korupsi. Hal ini berlanjut pada masa orde baru karena Indonesia sedang berkembang pesat di bidang ekonomi, politik, dan budaya. Dalam novel Orang-orang Proyek memberikan gambaran tentang praktek korupsi pada masa orde baru. Hal ini yang di ulas dalam project ini, bagaimana praktek tindak korupsi dan cara menagani bila ada teman sekerja yang mengajak untuk melakukan korupsi. Penulis menggunakan unsur intrinsik yaitu pada tema, karakter dan pesan untuk mengulas hal menarik yang menjadi kekuatan pada novel tersebut. Berdasarkan ulasan yang telah dilakukan, penulis menemukan bahwa terdapat tokoh utama yang tidak melakukan tindak korupsi