Why do axons differ in caliber?

CNS axons differ in diameter (d) by nearly 100-fold (∼0.1-10 μm); therefore, they differ in cross-sectional area (d(2)) and volume by nearly 10,000-fold. If, as found for optic nerve, mitochondrial volume fraction is constant with axon diameter, energy capacity would rise with axon volume, also as d(2). We asked, given constraints on space and energy, what functional requirements set an axon's diameter? Surveying 16 fiber groups spanning nearly the full range of diameters in five species (guinea pig, rat, monkey, locust, octopus), we found the following: (1) thin axons are most numerous; (2) mean firing frequencies, estimated for nine of the identified axon classes, are low for thin fibers and high for thick ones, ranging from ∼1 to >100 Hz; (3) a tract's distribution of fiber diameters, whether narrow or broad, and whether symmetric or skewed, reflects heterogeneity of information rates conveyed by its individual fibers; and (4) mitochondrial volume/axon length rises ≥d(2). To explain the pressure toward thin diameters, we note an established law of diminishing returns: an axon, to double its information rate, must more than double its firing rate. Since diameter is apparently linear with firing rate, doubling information rate would more than quadruple an axon's volume and energy use. Thicker axons may be needed to encode features that cannot be efficiently decoded if their information is spread over several low-rate channels. Thus, information rate may be the main variable that sets axon caliber, with axons constrained to deliver information at the lowest acceptable rate

Effects of Bni5 Binding on Septin Filament Organization

AbstractSeptins are a protein family found in all eukaryotes (except higher plants) that have roles in membrane remodeling and formation of diffusion barriers and as a scaffold to recruit other proteins. In budding yeast, proper execution of cytokinesis and cell division requires the formation of a collar of circumferential filaments at the bud neck. These filaments are assembled from apolar septin hetero-octamers. Currently, little is known about the mechanisms that control the arrangement and dynamics of septin structures. In this study, we utilized both Förster resonance energy transfer and electron microscopy to analyze the biophysical properties of the septin-binding protein Bni5 and how its association with septin filaments affects their organization. We found that the interaction of Bni5 with the terminal subunit (Cdc11) at the junctions between adjacent hetero-octamers in paired filaments is highly cooperative. Both the C-terminal end of Bni5 and the C-terminal extension of Cdc11 make important contributions to their interaction. Moreover, this binding may stabilize the dimerization of Bni5, which, in turn, forms cross-filament braces that significantly narrow, and impose much more uniform spacing on, the gap between paired filaments

UAS Literary & Arts Journal

Proof copy provided by Tidal Echoes.Tidal Echoes is an annual showcase of writers and artists with one thing in common: a life surrounded by the rainforests and waterways of Southeast Alaska.Davy Josh’s Note -- A Note from Chalise -- A Note from Emily Wall -- Brain Bucket -- Cephalic index -- A Gift of Fat for the Fire -- Our heroes have always been... -- Colorful Clouds -- Role Model -- Anchors -- Out My Window -- Adaptation -- Bookshelves -- In the Flow -- It’s a Small World Parade Float -- Sexy -- Death by Algebra -- Friend -- mirabile visu -- Exchange II -- F A D E -- Borne Alone -- Continuum -- The Week Before St. Valentine’s -- Bottled Up -- Untitled -- Early Morning Conspiracy Theory -- Westport -- Boulder Creek -- Jumping Off Rooftops -- Staying in the Room With Ernestine Hayes -- Blueberry -- After Neruda By Way of Bly (Tenure) -- Magic of Water -- Old Tom Steals the Light -- Old Tom Finds a Whale -- Research Project -- Guppy (boat) -- Arizona Spyder -- From Anthropomorphism to Zoomorphism -- Bus Stop -- December 1, 1955 -- Between Tides at Twilight -- Dementia -- Winter Ferry -- Coming into Auke Bay -- The Search for Jane Rogers -- Inlaid Tea Cups -- The Big Melt -- Kingsmill Reef -- Despite Man’s Best Efforts to Ruin It -- Roberts from Flume -- India Scarf -- Painted and Petrified -- Medicine Bag -- Merrill Field -- Deadly Kites -- Brazilian Ghetto -- Seattle Riff -- The Gospel Truth of My Gay Bird -- Signing the Divorce Papers -- Red Shades -- Holey Cow -- Untitled -- Series of Cedar Baskets -- A Conversation With Ranunculus -- Deconstruction -- Sandy Beach -- Threshold -- Oil and Honesty: An Interview with Artist and Professor David Woodie -- Mitkof #3 -- Still Life -- First Day of Fall -- Falling in the Garden -- After Finishing an Activities Report for the Dean -- Homage to Po Chü-I -- Nunc Dimittis -- Do Wise Men Have Bad Days? -- To the Plain Land -- Flood of ‘69 -- How a woman makes her own wine -- Untitled (translation from Russian) -- Existential Sestina -- It’s the knowing -- Blood and Guts -- Sometime Walking on the Beach -- Untitled -- Connecting the Pieces -- Hemlock -- Klawock Island -- Driven By the Tides -- Lunch -- The People -- Howling Dog -- Winter Cabin Lullaby -- Chain Gang -- A Review of Social Groups in Female Homo Sapiens as Exemplified by Mammary Restraint -- Apparatuses -- Douglas Island Bridge -- Going Home -- Author and Artist Biographie

Diving behavior of immature Steller sea lions (Eumetopias jubatus)

Understanding the ontogenetic relationship between juvenile Steller sea lions (Eumetopias jubatus) and their foraging habitat is key to understanding their relationship to available prey and ultimately their survival. We summarize dive and movement data from 13 young-of-the-year (YOY) and 12 yearling Steller sea lions equipped with satellite dive recorders in the Gulf of Alaska and Aleutian Islands (n=18), and Washington (n=7) from 1994 to 2000. A total of 1413 d of transmission (x =56.5 d, range: 14.5–104.1 d) were received. We recorded 222,073 dives, which had a mean depth of 18.4 m (range of means: 5.8−67.9 m; SD=16.4). Alaska YOY dived for shorter periods and at shallower depths (mean depth=7.7 m, mean duration=0.8 min, mean maximum depth=25.7 m, and maximum depth=252 m) than Alaska yearlings (x =16.6 m, 0=1.1 min, x = 63.4 m, 288 m), whereas Washington yearlings dived the longest and deepest (mean depth=39.4 m, mean duration=1.8 min, mean maximum depth=144.5 m, and maximum depth=328 m). Mean distance for 564 measured trips was 16.6 km; for sea lions ≤10 months of age, trip distance (7.0 km) was significantly less than for those >10 months of age (24.6 km). Mean trip duration for 10 of the 25 sea lions was 12.1 h; for sea lions ≤10 months of age, trip duration was 7.5 h and 18.1 h for those >10 months of age. We identified three movements types: long-range trips (>15 km and >20 h), short-range trips (<15 km and <20 h) during which the animals left and returned to the same site, and transits to other haul-out sites. Long-range trips started around 9 months of age and occurred most frequently around the assumed time of weaning, whereas short-range trips happened almost daily (0.9 trips/day, n=426 trips). Transits began as early as 7 months of age, occurred more often after 9 months of age, and ranged between 6.5 and 454 km. The change in dive characteristics coincided with the assumed onset of weaning. These yearling sea lion movement patterns and dive characteristics suggest that immature Steller sea lions are as capable of making the same types of movements as adults

Exile Vol. XL No. 1

38th Year Title Page by Carrie Horner \u2797 i Epigraph by Ezra Pound ii Table of Contents iii-iv Vertigo by Lisa Stillman \u2795 1 Departing Flight by Morgan Roper \u2794 2 Untitled by Lizzie Loud \u2795 3 Marietta by Craig McDonough \u2794 4 Interlaken by Kira A . Pollack \u2794 5 Why Nature Surprises Us by Josh Endicott \u2796 6-7 Untitled by Colin Mack \u2794 7 My Father by Matt Wanat \u2795 8 Legs In The Dust by Alison Stevens \u2795 9-11 Untitled by Lilly Streett \u2794 12 of cigarettes, saltwater and death... by Tricia B. Swearingen \u2794 13 Serendipity by Lizzie Lout \u2795 14 Untitled by Lilly Streett \u2794 15 Summer by Allison Lemieux \u2795 16 And the Rain Fell by Jeremy Aufrance \u2795 17-18 Main Street by Elise Gargarella \u2795 19 Füssen by Morgan Roper \u2794 20 Lightning on the Snow by Matt Wanat \u2795 21 A discussion of 12 year-old murders, of course by Jeremy Aufrance \u2795 22 Get your hands off my hat by Jamie Oliver \u2794 23 The Hero by Sara Sterling Ely \u2796 24-26 Punker Dave by Trevett Allen \u2795 27 still looking for the perfect line by ryan shafer \u2794 28-29 Untitled by Lizzie Loud \u2795 30 Civil War by Katherine Anne Campo \u2794 31 Disposable belief by ryan shafer \u2794 32-33 Schizophrenic Sylvia by Maria Mohiuddin \u2795 34 Excerpts from Revolutions, a novel by Marcu McLaughlin \u2794 35-36 Untitled by Keith Chapman \u2795 37 The Survivors by Kira A. Pollack \u2794 38 Days of Prophecy by Trey Dunham \u2794 39 Untitled by Carrie Horner \u2797 40 What to do by Christopher Harnish \u2794 41 Familiar Stranger by Lisa Stillman \u2795 42-46 Untitled by John Salter \u2797 47 On Meeting Emma by Allison Lemieux \u2795 48 Nude Figure by James Oliver \u2794 49 Tathagata by Leslie Dana Wells \u2794 50 On Fences and My Dogs by Christopher Harnish \u2794 51 Editorial Board 52 Cover, Kira Pollack \u2794 -iv Editorial decision is shared equally among the Editorial Board. -5

White Matter Hyperintensities in Vascular Contributions to Cognitive Impairment and Dementia (VCID): Knowledge Gaps and Opportunities

White matter hyperintensities (WMHs) are frequently seen on brain magnetic resonance imaging scans of older people. Usually interpreted clinically as a surrogate for cerebral small vessel disease, WMHs are associated with increased likelihood of cognitive impairment and dementia (including Alzheimer\u27s disease [AD]). WMHs are also seen in cognitively healthy people. In this collaboration of academic, clinical, and pharmaceutical industry perspectives, we identify outstanding questions about WMHs and their relation to cognition, dementia, and AD. What molecular and cellular changes underlie WMHs? What are the neuropathological correlates of WMHs? To what extent are demyelination and inflammation present? Is it helpful to subdivide into periventricular and subcortical WMHs? What do WMHs signify in people diagnosed with AD? What are the risk factors for developing WMHs? What preventive and therapeutic strategies target WMHs? Answering these questions will improve prevention and treatment of WMHs and dementia

Long-acting injectable Cabotegravir + Rilpivirine for HIV maintenance therapy: Week 48 pooled analysis of phase 3 ATLAS and FLAIR trials

BACKGROUND: Long-acting (LA) injectable regimens are a potential therapeutic option in people living with HIV-1. SETTING: ATLAS (NCT02951052) and FLAIR (NCT02938520) were 2 randomized, open-label, multicenter, multinational phase 3 studies. METHODS: Adult participants with virologic suppression (plasma HIV-1 RNA &lt;50 copies/mL) were randomized (1:1) to continue with their current antiretroviral regimen (CAR) or switch to the long-acting (LA) regimen of cabotegravir (CAB) and rilpivirine (RPV). In the LA arm, participants initially received oral CAB + RPV once-daily for 4 weeks to assess individual safety and tolerability, before starting monthly injectable therapy. The primary endpoint of this combined analysis was antiviral efficacy at week 48 (FDA Snapshot algorithm: noninferiority margin of 4% for HIV-1 RNA ≥50 copies/mL). Safety, tolerability, and confirmed virologic failure (2 consecutive plasma HIV-1 RNA ≥200 copies/mL) were secondary endpoints. RESULTS: The pooled intention-to-treat exposed population included 591 participants in each arm [28% women (sex at birth), 19% aged ≥50 years]. Noninferiority criteria at week 48 were met for the primary (HIV-1 RNA ≥50 copies/mL) and key secondary (HIV-1 RNA &lt;50 copies/mL) efficacy endpoints. Seven individuals in each arm (1.2%) developed confirmed virologic failure; 6/7 (LA) and 3/7 (CAR) had resistance-associated mutations. Most LA recipients (83%) experienced injection site reactions, which decreased in incidence over time. Injection site reactions led to the withdrawal of 6 (1%) participants. The serious adverse event rate was 4% in each arm. CONCLUSION: This combined analysis demonstrates monthly injections of CAB + RPV LA were noninferior to daily oral CAR for maintaining HIV-1 suppression

Toward High Performance Computing Education

High Performance Computing (HPC) is the ability to process data and perform complex calculations at extremely high speeds. Current HPC platforms can achieve calculations on the order of quadrillions of calculations per second with quintillions on the horizon. The past three decades witnessed a vast increase in the use of HPC across different scientific, engineering and business communities, for example, sequencing the genome, predicting climate changes, designing modern aerodynamics, or establishing customer preferences. Although HPC has been well incorporated into science curricula such as bioinformatics, the same cannot be said for most computing programs. This working group will explore how HPC can make inroads into computer science education, from the undergraduate to postgraduate levels. The group will address research questions designed to investigate topics such as identifying and handling barriers that inhibit the adoption of HPC in educational environments, how to incorporate HPC into various curricula, and how HPC can be leveraged to enhance applied critical thinking and problem solving skills. Four deliverables include: (1) a catalog of core HPC educational concepts, (2) HPC curricula for contemporary computing needs, such as in artificial intelligence, cyberanalytics, data science and engineering, or internet of things, (3) possible infrastructures for implementing HPC coursework, and (4) HPC-related feedback to the CC2020 project