Annual variation in predation risk is related to the direction of selection for brain size in the wild

The direction of predator-mediated selection on brain size is debated. However, the speed and the accuracy of performing a task cannot be simultaneously maximized. Large-brained individuals may be predisposed to accurate but slow decision-making, beneficial under high predation risk, but costly under low risk. This creates the possibility of temporally fluctuating selection on brain size depending on overall predation risk. We test this idea in nesting wild eider females (Somateria mollissima), in which head volume is tightly linked to brain mass (r(2) = 0.73). We determined how female relative head volume relates to survival, and characterized the seasonal timing of predation. Previous work suggests that relatively large-brained and small-brained females make slow versus fast nest-site decisions, respectively, and that predation events occur seasonally earlier when predation is severe. Large-brained, late-breeding females may therefore have higher survival during high-predation years, but lower survival during safe years, assuming that predation disproportionately affects late breeders in such years. Relatively large-headed females outsurvived smaller-headed females during dangerous years, whereas the opposite was true in safer years. Predation events occurred relatively later during safe years. Fluctuations in the direction of survival selection on relative brain size may therefore arise due to brain-size dependent breeding phenology.Peer reviewe

N-Acetylcysteine as modulator of the essential trace elements copper and zinc

N-acetylcysteine (NAC) is a frequently prescribed drug and known for its metal chelating capability. However, to date it is not well characterized whether NAC intake affects the homeostasis of essential trace elements. As a precursor of glutathione (GSH), NAC also has the potential to modulate the cellular redox homeostasis. Thus, we aimed to analyze effects of acute and chronic NAC treatment on the homeostasis of copper (Cu) and zinc (Zn) and on the activity of the redox-sensitive transcription factor Nrf2. Cells were exposed to 1 mM NAC and were co-treated with 50 µM Cu or Zn. We showed that NAC treatment reduced the cellular concentration of Zn and Cu. In addition, NAC inhibited the Zn-induced Nrf2 activation and limited the concomitant upregulation of cellular GSH concentrations. In contrast, mice chronically received NAC via drinking water (1 g NAC/100 mL). Cu and Zn concentrations were decreased in liver and spleen. In the duodenum, NQO1, TXNRD, and SOD activities were upregulated by NAC. All of them can be induced by Nrf2, thus indicating a putative Nrf2 activation. Overall, NAC modulates the homeostasis of Cu and Zn both in vitro and in vivo and accordingly affects the cellular redox balance

Constitution and conductivity of metalloporphyrin tapes

Metalloporphyrin tapes form in a solvent-free oxidative chemical vapor deposition process on glass substrates. The metal center (M = NiII, CuII, ZnII, CoII, PdII, FeIIICl, 2H) in the 5,15-disubstituted porphyrin monomer affects the initial C–C coupling step and consequently the formation of triply or doubly linked porphyrin tapes as well as the interchain interaction in the tape as shown by optical spectroscopy, high resolution mass spectrometry and X-ray photoelectron spectroscopy. Optical spectroscopy and conductive atomic force microscopy reveal that these factors influence the near-infrared absorbance and the electrical conductivity of the films. Consequently, the metal ion of the metalloporphyrin allows tuning of the macroscopic properties of the thin films composed of metalloporphyrin tapes

Existential witness extraction in classical realizability and via a negative translation

We show how to extract existential witnesses from classical proofs using Krivine's classical realizability---where classical proofs are interpreted as lambda-terms with the call/cc control operator. We first recall the basic framework of classical realizability (in classical second-order arithmetic) and show how to extend it with primitive numerals for faster computations. Then we show how to perform witness extraction in this framework, by discussing several techniques depending on the shape of the existential formula. In particular, we show that in the Sigma01-case, Krivine's witness extraction method reduces to Friedman's through a well-suited negative translation to intuitionistic second-order arithmetic. Finally we discuss the advantages of using call/cc rather than a negative translation, especially from the point of view of an implementation.Comment: 52 pages. Accepted in Logical Methods for Computer Science (LMCS), 201

Role of multiparametric magnetic resonance imaging in early detection of prostate cancer.

UNLABELLED: Most prostate cancers (PC) are currently found on the basis of an elevated PSA, although this biomarker has only moderate accuracy. Histological confirmation is traditionally obtained by random transrectal ultrasound guided biopsy, but this approach may underestimate PC. It is generally accepted that a clinically significant PC requires treatment, but in case of an non-significant PC, deferment of treatment and inclusion in an active surveillance program is a valid option. The implementation of multiparametric magnetic resonance imaging (mpMRI) into a screening program may reduce the risk of overdetection of non-significant PC and improve the early detection of clinically significant PC. A mpMRI consists of T2-weighted images supplemented with diffusion-weighted imaging, dynamic contrast enhanced imaging, and/or magnetic resonance spectroscopic imaging and is preferably performed and reported according to the uniform quality standards of the Prostate Imaging Reporting and Data System (PIRADS). International guidelines currently recommend mpMRI in patients with persistently rising PSA and previous negative biopsies, but mpMRI may also be used before first biopsy to improve the biopsy yield by targeting suspicious lesions or to assist in the selection of low-risk patients in whom consideration could be given for surveillance. TEACHING POINTS: ? MpMRI may be used to detect or exclude significant prostate cancer. ? MpMRI can guide targeted rebiopsy in patients with previous negative biopsies. ? In patients with negative mpMRI consideration could be given for surveillance. ? MpMRI may add valuable information for the optimal treatment selection

Upaya Meningkatkan Hasil Belajar Matematika Materi Penjumlahan di Kelas V MI Muhammadiyah Sipedang Kecamatan Banjarmangu Kabupaten Banjarnegara dengan Menggunakan Metode The Power of Two

Skripsi ini dilatarbelakangi oleh pembelajaran matematika di Kelas V MI Muhammadiyah Sipedang Kecmatan Banjarmangu Kabupaten Banjar Negara dilakukan dengan menggunakan metode konvensional dengan ceramah, tanya jawab dan resitasi yang tentunya menjadikan siswa tidak mengalami pembelajarannya langsung dan mempersulit siswa dalam memahami materi matematika, Untuk itu, sebagai tenaga pendidik harus bisa mengurangi dan menghilangkan persepsi yang salah tersebut, dengan cara memilih metode pembelajaran yang lebih bervariasi dan tepat, Salah satu metode pembelajaran yang memenuhi kriteria adalah metode the power of two. Studi ini dimaksudkan untuk menjawab permasalahan: 1) bagaimana penerapan metode the power of two pada mata pelajaran matematika materi penjumlahan di kelas V MI Muhammadiyah Sipedang Kecmatan Banjarmangu Kabupaten Banjar negara? 2) apakah metode the power of two dapat meningkatkan hasil belajar matematika materi penjumlahan di kelas V MI Muhammadiyah Sipedang Kecmatan Banjarmangu Kabupaten Banjar negara? Permasalahan tersebut di bahas melalui penelitian tindakan kelas yang dilakukan melalui 2 siklus dengan setiap siklus tahapannya adalah perencanaan, tindakan, observasi dan refleksi. Hasil penelitian menunjukkan bahwa 1) Penerapan metode the power of two pada mata pelajaran matematika materi penjumlahan di kelas V MI Muhammadiyah Sipedang Kecamatan Banjarmangu Kabupaten Banjar negara dilakukan dengan melaksanakan pembelajaran yang memanfaatkan kekuatan dua siswa atau berpasangan untuk menyelesaikan masalah yang diberikan guru, selain itu pasangan tersebut juga mencoba menjawab pertanyaan dari pasangan lain sehingga terjadilah proses saling ketergantungan positif diantara pasangan. 2) Metode the power of two dapat mengurangi kesulitan belajar matematika materi penjumlahan di kelas V MI Muhammadiyah Sipedang Kecamatan Banjarmangu Kabupaten Banjar negara, hal ini terlihat dari hasil belajar yang di dapat siswa setelah melakukan tindakan dimana pada pra siklus ketuntasan ada 15 siswa atau 47%, pada siklus I ketuntasan ada 21 siswa atau 66% dan pada siklus II ketuntasan sudah mencapai 28 siswa atau 88%, begitu juga keaktifan belajar siswa juga mengalami kenaikan dimana pada siklus I ada 15 siswa atau 47 dan pada siklus II sudah mencapai 27 siswa atau 84