When Zombies Attack!: Mathematical Modelling of an Outbreak of Zombie Infection

Infectious Disease Modelling Research Progress,
eds. J.M. Tchuenche and C. Chiyaka,
Nova Science Publishers, Inc.
pp. 133-150, 2009

Philip Munz [1], Ioan Hudea [1], Joe Imad [2], Robert J. Smith? [3]

[1] School of Mathematics and Statistics, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada
[2] Department of Mathematics, The University of Ottawa, 585 King Edward Ave, Ottawa ON K1N 6N5, Canada
[2] Department of Mathematics and Faculty of Medicine, The University of Ottawa, 585 King Edward Ave, Ottawa ON K1N 6N5, Canada

Abstract

Zombies are a popular figure in pop culture/entertainment and they are usually portrayed as being brought about through an outbreak or epidemic. Consequently, we model a zombie attack, using biological assumptions based on popular zombie movies. We introduce a basic model for zombie infection, determine equilibria and their stability, and illustrate the outcome with numerical solutions. We then refine the model to introduce a latent period of zombification, whereby humans are infected, but not infectious, before becoming undead. We then modify the model to include the effects of possible quarantine or a cure. Finally, we examine the impact of regular, impulsive reductions in the number of zombies and derive conditions under which eradication can occur. We show that only quick, aggressive attacks can stave off the doomsday scenario: the collapse of society as zombies overtake us all.

https://www.novapublishers.com/catalog/product_info.php?products_id=9750

Fellatio by Fruit Bats Prolongs Copulation Time

PLoS One. 2009; 4(10): e7595.
Published online Oct 28, 2009. doi: 10.1371/journal.pone.0007595

Min Tan [1,3], Gareth Jones [2], Guangjian Zhu [1], Jianping Ye [1,3], Tiyu Hong [1,3], Shanyi Zhou [3], Shuyi Zhang [4], and Libiao Zhang [1]

[1] Guangdong Entomological Institute, Guangzhou, China
[2] School of Biological Sciences, University of Bristol, Bristol, United Kingdom
[3] College of Life Sciences, Guangxi Normal University, Guilin, China
[4] School of Life Sciences, East China Normal University, Shanghai, China

Oral sex is widely used in human foreplay, but rarely documented in other animals. Fellatio has been recorded in bonobos Pan paniscus, but even then functions largely as play behaviour among juvenile males. The short-nosed fruit bat Cynopterus sphinx exhibits resource defence polygyny and one sexually active male often roosts with groups of females in tents made from leaves. Female bats often lick their mate's penis during dorsoventral copulation. The female lowers her head to lick the shaft or the base of the male's penis but does not lick the glans penis which has already penetrated the vagina. Males never withdrew their penis when it was licked by the mating partner. A positive relationship exists between the length of time that the female licked the male's penis during copulation and the duration of copulation. Furthermore, mating pairs spent significantly more time in copulation if the female licked her mate's penis than if fellatio was absent. Males also show postcopulatory genital grooming after intromission. At present, we do not know why genital licking occurs, and we present four non-mutually exclusive hypotheses that may explain the function of fellatio in C. sphinx.

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0007595

The Manga Guide to Molecular Biology

The Manga Guide to Molecular Biology
Published September 4th 2009 by No Starch Press

Masaharu Takemura
Sakura, Becom Ltd., Becom Co., Ltd.

Rin and Ami have been skipping molecular biology class all semester, and Professor Moro has had enough-he's sentencing them to summer school on his private island. But they're in store for a special lesson. Using Dr. Moro's virtual reality machine to travel inside the human body, they'll get a close-up look at the fascinating world of molecular biology.

Join them in The Manga Guide to Molecular Biology, and learn all about DNA, RNA, proteins, amino acids, and more. Along the way, you'll see chemical reactions first-hand and meet entertaining characters like Enzyme Man and Drinkzilla, who show how the liver metabolizes alcohol.

http://www.goodreads.com/book/show/6464275-the-manga-guide-to-molecular-biology

http://books.google.nl/books?id=3eIf_1sinSgC&printsec=frontcover

http://www.scribd.com/doc/18613038/The-Manga-Guide-to-Molecular-Biology-Excerpt

Swearing as a response to pain

Neuroreport. 5 August 2009 - Volume 20 - Issue 12 - pp 1056-1060
doi: 10.1097/WNR.0b013e32832e64b1

Stephens, Richard; Atkins, John; Kingston, Andrew

School of Psychology, Keele University, Keele, Staffordshire, UK

Abstract

Although a common pain response, whether swearing alters individuals' experience of pain has not been investigated. This study investigated whether swearing affects cold-pressor pain tolerance (the ability to withstand immersing the hand in icy water), pain perception and heart rate. In a repeated measures design, pain outcomes were assessed in participants asked to repeat a swear word versus a neutral word. In addition, sex differences and the roles of pain catastrophising, fear of pain and trait anxiety were explored. Swearing increased pain tolerance, increased heart rate and decreased perceived pain compared with not swearing. However, swearing did not increase pain tolerance in males with a tendency to catastrophise. The observed pain-lessening (hypoalgesic) effect may occur because swearing induces a fight-or-flight response and nullifies the link between fear of pain and pain perception.

http://journals.lww.com/neuroreport/abstract/2009/08050/swearing_as_a_response_to_pain.4.aspx

Are full or empty beer bottles sturdier and does their fracture-threshold suffice to break the human skull?

Journal of Forensic and Legal Medicine
Volume 16, Issue 3, April 2009, Pages 138–142

Stephan A. Bolliger, MD (Senior Forensic Pathologist), Steffen Ross, MD (Radiologist), Lars Oesterhelweg, MD (Forensic Pathologist), Michael J. Thali, MD (Professor, Director, Forensic Pathologist), Beat P. Kneubuehl, PhD (Physicist)

Centre for Forensic Imaging and Virtopsy, Institute of Forensic Medicine, University of Bern, IRM, Buehlstrasse 20, CH-3012 Bern, Switzerland

Abstract

Beer bottles are often used in physical disputes. If the bottles break, they may give rise to sharp trauma. However, if the bottles remain intact, they may cause blunt injuries. In order to investigate whether full or empty standard half-litre beer bottles are sturdier and if the necessary breaking energy surpasses the minimum fracture-threshold of the human skull, we tested the fracture properties of such beer bottles in a drop-tower.

Full bottles broke at 30 J impact energy, empty bottles at 40 J. These breaking energies surpass the minimum fracture-threshold of the human neurocranium. Beer bottles may therefore fracture the human skull and therefore serve as dangerous instruments in a physical dispute.

Keywords

Breaking energy threshold; Beer bottles; Blunt head trauma

http://www.sciencedirect.com/science/article/pii/S1752928X08001728

Earwax (cerumen) might be formulated into a safe and biodegradable insect repellent

Medical Hypotheses
Volume 72, Issue 3 , Pages 370-371, March 2009
doi: 10.1016/j.mehy.2008.09.036

Somaieh Ahmadian, Mohammad Amin Abolghassemi Fakhree

Research Center for Pharmaceutical Nanotechnology, Tabriz University (Medical Sciences), Daneshgah Street, Tabriz, Iran
Gifted and Talented Students Office, Educational Development Center, Tabriz University (Medical Sciences), Tabriz, Iran

Some of the most common life threatening insect-borne diseases include malaria, leshmaniasis and yellow fever which can be prevented or treated with different non-therapeutic/therapeutic procedures such as use of mosquito net, insect repellent (IR), vector controlling strategies, vaccination and implementation of pharmaceuticals. Among these methods IR provides the cheapest and easiest one to use. Active ingredients of IR usually include N,N-diethyl-3-methylbenzamide (DEET), botanical extracts and picaridin. However still some concerns remain e.g. DEET is not biodegradable, has side effects on skin, cardiovascular and central nervous system and is not applicable in under 3 years old children and animals.

Cerumen is produced by glands that are located on the outer third of the ear canal, has a characteristic of bitter taste and protection of ear which is known as IR, bactericide, fungicide and antivirus. It has lipidic and non-lipidic fractions; lipid fraction is consisted of squalene, cholesterol esters, wax esters, triacylglycerols, fatty acids, cholesterol, ceramides, cholesterol sulfate, and several unidentified polar components.

The authors would like to hypothesize an IR made from fatty acids and steroids of cerumen. Whereas masking skin odor and presenting a bad taste is the mechanism of action for IRs. Also fatty acids considered as major ingredient of Neem Oil as repellent, a screening of lipid fraction with the aim of discovering which components have the major effect is recommended.

The advantages of the proposed formulation will be easy of production, biodegradability and safety of use in adults, children and animals.

Beside, proteins and peptides in cerumen could be further analyzed in order to investigate a nontoxic multi-spectrum antibiotic; possessing bactericidal, fungicidal and antiviral activity.

http://www.medical-hypotheses.com/article/S0306-9877%2808%2900500-8/abstract

Effects of cocaine on honey bee dance behaviour

J Exp Biol
Jan 15, 2009; 212(2): 163–168
doi:  10.1242/jeb.025361

Andrew B. Barron [1,2,*], Ryszard Maleszka [1], Paul G. Helliwell [1] and Gene E. Robinson [2]

[1] ARC Centre for Molecular Genetics of Development, Research School of Biological Sciences, Australian National University, Canberra, ACT 2601, Australia
[2] Department of Entomology and Neuroscience Program, University of Illinois at Urbana-Champaign, 505 S. Goodwin Avenue, Urbana, IL 61801, USA

* Author for correspondence at present address: Centre for the Integrative Study of Animal Behaviour, Macquarie University, Sydney NSW 2109, Australia

Summary

The role of cocaine as an addictive drug of abuse in human society is hard to reconcile with its ecological role as a natural insecticide and plant-protective compound, preventing herbivory of coca plants (Erythroxylum spp.). This paradox is often explained by proposing a fundamental difference in mammalian and invertebrate responses to cocaine, but here we show effects of cocaine on honey bees (Apis mellifera L.) that parallel human responses. Forager honey bees perform symbolic dances to advertise the location and value of floral resources to their nest mates. Treatment with a low dose of cocaine increased the likelihood and rate of bees dancing after foraging but did not otherwise increase locomotor activity. This is consistent with cocaine causing forager bees to overestimate the value of the floral resources they collected. Further, cessation of chronic cocaine treatment caused a withdrawal-like response. These similarities likely occur because in both insects and mammals the biogenic amine neuromodulator systems disrupted by cocaine perform similar roles as modulators of reward and motor systems. Given these analogous responses to cocaine in insects and mammals, we propose an alternative solution to the paradox of cocaine reinforcement. Ecologically, cocaine is an effective plant defence compound via disruption of herbivore motor control but, because the neurochemical systems targeted by cocaine also modulate reward processing, the reinforcing properties of cocaine occur as a `side effect'.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2720998/