Splitting probabilities as a test of reaction coordinate choice in single-molecule experiments

To explain the observed dynamics in equilibrium single-molecule measurements of biomolecules, the experimental observable is often chosen as a putative reaction coordinate along which kinetic behavior is presumed to be governed by diffusive dynamics. Here, we invoke the splitting probability as a test of the suitability of such a proposed reaction coordinate. Comparison of the observed splitting probability with that computed from the kinetic model provides a simple test to reject poor reaction coordinates. We demonstrate this test for a force spectroscopy measurement of a DNA hairpin

Freezing Transition of Random Heteropolymers Consisting of an Arbitrary Set of Monomers

Mean field replica theory is employed to analyze the freezing transition of random heteropolymers comprised of an arbitrary number ($q$) of types of monomers. Our formalism assumes that interactions are short range and heterogeneity comes only from pairwise interactions, which are defined by an arbitrary $q \times q$ matrix. We show that, in general, there exists a freezing transition from a random globule, in which the thermodynamic equilibrium is comprised of an essentially infinite number polymer conformations, to a frozen globule, in which equilibrium ensemble is dominated by one or very few conformations. We also examine some special cases of interaction matrices to analyze the relationship between the freezing transition and the nature of interactions involved.Comment: 30 pages, 1 postscript figur

Hubungan Faktor Internal dengan Kinerja Pegawai di Rumah Sakit Umum Daerah Wangaya Kota Denpasar

Kinerja adalah suatu bentuk hasil kerja yang dapat dicapai oleh seorang pegawai demi mencapai tujuan organisasi atau Perusahaan yang dapat diukur melalui indikator-indikator pengukuran kinerja. Faktor internal pegawai sangat penting diperhatikan dalam rangka pencapaian tujuan organisasi secara optimal diantaranya faktor pendidikan, pengalaman kerja, disiplin serta motivasi. Penelitian ini bertujuan untuk mengetahui hubungan antara faktor internal dengan kinerja pegawai di Rumah Sakit Umum Daerah Wangaya Kota Denpasar tahun 2013. Penelitian ini merupakan penelitian analitik kuantitatif dengan rancangan penelitian cross sectional. Sampel penelitian ini berjumlah 90 orang yang dipilih dengan teknik proportionate stratified random sampling. Berdasarkan gambaran karakteristik responden, sebagian besar responden memiliki tingkat pendidikan D.III dan berstatus sebagai Pegawai Negeri Sipil. Data dikumpulkan melalui kuesioner terstruktur kemudian dianalisis melalui uji chi square dengan tingkat kepercayaan 95% atau ?=0,05. Berdasarkan hasil penelitian menunjukkan ada hubungan bermakna antara pendidikan dengan kinerja pegawai di RSUD Wangaya dengan nilai p = 0.000. Faktor pengalaman kerja memiliki hubungan bermakna dengan kinerja pegawai dengan nilai p = 0.000. Ada hubungan bermakna antara disiplin dengan kinerja pegawai di RSUD Wangaya dengan nilai p = 0.000. Serta ada hubungan bermakna antara motivasi dengan kinerja pegawai di RSUD Wangaya (p = 0.000). Kesimpulan dari penelitian ini yaitu faktor pendidikan, pengalaman kerja, disiplin serta kinerja memiliki hubungan yang bermakna dengan kinerja pegawai di RSUD Wangaya. Saran pada penelitian ini adalah sebaiknya pihak RSUD Wangaya lebih meningkatkan dan mengantisipasi terjadinya pelanggaran disiplin yang menyebabkan penurunan kinerja dengan melakukan pengawasan dan evaluasi kinerja secara teratur dan berkesinambungan

Is Heteropolymer Freezing Well Described by the Random Energy Model?

It is widely held that the Random Energy Model (REM) describes the freezing transition of a variety of types of heteropolymers. We demonstrate that the hallmark property of REM, statistical independence of the energies of states over disorder, is violated in different ways for models commonly employed in heteropolymer freezing studies. The implications for proteins are also discussed.Comment: 4 pages, 3 eps figures To appear in Physical Review Letters, May 199

Enhancing electrochemical intermediate solvation through electrolyte anion selection to increase nonaqueous Li-O2_2 battery capacity

Among the 'beyond Li-ion' battery chemistries, nonaqueous Li-O$_2$ batteries have the highest theoretical specific energy and as a result have attracted significant research attention over the past decade. A critical scientific challenge facing nonaqueous Li-O$_2$ batteries is the electronically insulating nature of the primary discharge product, lithium peroxide, which passivates the battery cathode as it is formed, leading to low ultimate cell capacities. Recently, strategies to enhance solubility to circumvent this issue have been reported, but rely upon electrolyte formulations that further decrease the overall electrochemical stability of the system, thereby deleteriously affecting battery rechargeability. In this study, we report that a significant enhancement (greater than four-fold) in Li-O$_2$ cell capacity is possible by appropriately selecting the salt anion in the electrolyte solution. Using $^7$Li nuclear magnetic resonance and modeling, we confirm that this improvement is a result of enhanced Li$^+$ stability in solution, which in turn induces solubility of the intermediate to Li$_2$O$_2$ formation. Using this strategy, the challenging task of identifying an electrolyte solvent that possesses the anti-correlated properties of high intermediate solubility and solvent stability is alleviated, potentially providing a pathway to develop an electrolyte that affords both high capacity and rechargeability. We believe the model and strategy presented here will be generally useful to enhance Coulombic efficiency in many electrochemical systems (e.g. Li-S batteries) where improving intermediate stability in solution could induce desired mechanisms of product formation.Comment: 22 pages, 5 figures and Supporting Informatio

CARVE: Practical Security-Focused Software Debloating Using Simple Feature Set Mappings

Software debloating is an emerging field of study aimed at improving the security and performance of software by removing excess library code and features that are not needed by the end user (called bloat). Software bloat is pervasive, and several debloating techniques have been proposed to address this problem. While these techniques are effective at reducing bloat, they are not practical for the average user, risk creating unsound programs and introducing vulnerabilities, and are not well suited for debloating complex software such as network protocol implementations. In this paper, we propose CARVE, a simple yet effective security-focused debloating technique that overcomes these limitations. CARVE employs static source code annotation to map software features source code, eliminating the need for advanced software analysis during debloating and reducing the overall level of technical sophistication required by the user. CARVE surpasses existing techniques by introducing debloating with replacement, a technique capable of preserving software interoperability and mitigating the risk of creating an unsound program or introducing a vulnerability. We evaluate CARVE in 12 debloating scenarios and demonstrate security and performance improvements that meet or exceed those of existing techniques.Comment: 8 pages, 4 figures, 2 tables, 1 appendi