Long-term development of experimental mixtures of Scots pine (Pinus sylvestris L.) and silver birch (Betula pendula Roth.) in northern Britain

The Caledonian pinewoods of northern Scotland are a priority conservation habitat in Europe which are dominated by Scots pine (Pinus sylvestris), but varying proportions of a number of broadleaved species such as silver birch (Betula pendula) can occur in these forests. Better understanding of the dynamics of mixed Scots pine-birch stands would be helpful in informing current initiatives to restore and increase the area of the pinewood ecosystem. Some evidence is provided by two experiments established in the 1960s which compared plots of pure Scots pine and pure birch with two treatments where the two species were mixed in 3:1 and 1:1 ratios. Some fifty years later, Scots pine was the more vigorous of the two species in these experiments, being both taller and significantly larger in diameter. The highest basal area was generally found in the pure Scots pine plots and the values in the mixed plots tended to be intermediate between those of the two component species. Examination of the growth in the mixed plots showed a slight, but non-significant, tendency towards overyielding. This appeared to be due to Scots pine growth being better than predicted, while that of birch was slightly less than predicted. These results suggest that in these mixtures, which are composed of two light demanding species, the main mechanism driving long-term performance is competition for light and there is little evidence of any complementary effect. These results suggest that any strategy seeking to increase the long-term representation of broadleaves such as birch in the Caledonian pinewoods will need to create discrete blocks that are large enough to withstand the competitive pressures exerted by the pine

The Grizzly, March 4, 1988

Pot of Gold at End of Goal • Variety of Plans Announced by Board • Class of 1988 Works Toward Graduation • Letters: Trashed Campus Disgusts Zimmer; Jamison Brings Stew to Boil; Student Steamed at Noise; Shooting STAR Sends Sparks • Matters Grab Sixth Place Finish • Men Swim to an Impressive Finish • \u27Mer Chicks End on Upbeat Note • Women\u27s Lacrosse Takes Aim at Regaining National Title • Gymnasts ECAC Bound • German Wrestlers to Visit Ursinus College in Tourhttps://digitalcommons.ursinus.edu/grizzlynews/1207/thumbnail.jp

The Grizzly, February 21, 1986

It\u27s Bid Day!: Three Weeks of Frat Pledging get Underway • Suite Living in Reimert • Unique Paper Sculptures get Positive Reactions • Intra-Mural Season Opens • Demerits, Profanity, Attack on Deans Mark Alcohol Policing in the Past • Disease, Dissent, Dissemblance: Mills of Bureaucracy Grind Exceeding Slow, But Grind Old Folks Exceeding Fine • U.C. Hosts MAC Wrestling Tourney • Men\u27s Track: Strong MAC Lineup • Gym Women get Trimmed • Missing Refs, Fan Riot: The Best Game Ever ? • SAC Funds Available • Women\u27s Studies Surveyhttps://digitalcommons.ursinus.edu/grizzlynews/1158/thumbnail.jp

The Grizzly, October 3, 1986

Berman Collection • Former Phila. Cop Anchors Security Force • Letters: Not Ones to Dampen Festive Spirits; What is this thing?; It\u27s Aluminating! • Not a Dichotomous Community • Temple Fires Conversation Perhaps More Than Unger Imagined • Grizzlies Pound Green Terrors • Hockey Upsets Temple, Falls to Lock Haven • Nolan Institutes In-Service RA Training • Soccer: Bears Choose Tri-Captains • Parker Parked in Injury Garage • Athlete of the Week: Schoenherr Shows her Stuff • Resume Workshophttps://digitalcommons.ursinus.edu/grizzlynews/1170/thumbnail.jp

The Grizzly, February 5, 1988

Cavorting Cop Caught • Lewis Disclaims Labels at Forum • Rock\u27N America • Patterns Campaign Nears Completion • Hockey Held as Hokey • Contra-versial Censorship Irks Student • History Department Interviews a New Way • Concert Features Christian Music • Summer Study in France a Fun-do • Notes: R.A. Rap Session Announced; Presidency Probers Convene; ALF Re-runs Rewarding; Child Safety Course Offered • Men\u27s Hoopsters Suffer Temporary Setback • Track Team Making Great Strides • Record Books Rewritten • U.C. Matters: Wrestling Tough and Confident • Men \u27Mers Holding Their Ownhttps://digitalcommons.ursinus.edu/grizzlynews/1203/thumbnail.jp

The Grizzly, October 3, 1986

Berman Collection • Former Phila. Cop Anchors Security Force • Letters: Not Ones to Dampen Festive Spirits; What is this thing?; It\u27s Aluminating! • Not a Dichotomous Community • Temple Fires Conversation Perhaps More Than Unger Imagined • Grizzlies Pound Green Terrors • Hockey Upsets Temple, Falls to Lock Haven • Nolan Institutes In-Service RA Training • Soccer: Bears Choose Tri-Captains • Parker Parked in Injury Garage • Athlete of the Week: Schoenherr Shows her Stuff • Resume Workshophttps://digitalcommons.ursinus.edu/grizzlynews/1170/thumbnail.jp

The Grizzly, October 10, 1986

POD / LCB Dysfunction • Salinger Files Suit • Trials Near End on the Trail to Sisterhood • Letters: Milking Them for Their Money; Airing Dirty Laundry; We Value our Pledges • Ursinus Lends Itself to Powerful Homecoming Pull • Musser on the Move: a Resident\u27s Recollection • Hooking That Big 12 Incher • Grizzlies Gain Respect in Heartbreaking 30-25 Loss • Bear Booters Losing Games and Players • Lady Bears Suffer Their First Shutout Then Beat Lafayette in OT • Impressive Performances Power X-Country to 2-0 • NCAA Champs Honored at Homecoming Dinner • Athlete of the Week: Runner Mike Griffin • Lady Runners Keep Shining • Feature on the Feature Writer • Four of UC\u27s Best To Sing at PCC Festival • Extra-Curricular Activities: The Bicycle Club • Catch the Big Edsel Band!https://digitalcommons.ursinus.edu/grizzlynews/1171/thumbnail.jp

The Grizzly, April 18, 1986

The Bomb is Dropped; Policy Could Can Kegs • Admissions Video to Draw High School Seniors • CAB Spring Weekend Twists Around the Corner! • Administration\u27s Letter: Clearing Up the Cloudy Water • Get Your Ruby • Proposed Alcohol Regulations • Political Science\u27s Fitzpatrick to Focus on Constitution • Richter Joins Pavarotti • Greek Week Results • College Republicans Meet in Harrisburg • Perreten in Select Group to Interpret Humanities • Novack to Study Technology\u27s Effects on French Life • Lift-A-Thon: Pressing Weights for Progress • Women\u27s LAX Takes Two • Linksters Drive to 7-1 Record • Men\u27s LAX Strong at 5-2 • Rowson a Threat for Gold in Five Events • A Sterling Suggestion! Brown to be Tattooed • O\u27Toole Hurdles School Record • Men\u27s Tennis • Bears Battle Back • Hadler\u27s Medical Serieshttps://digitalcommons.ursinus.edu/grizzlynews/1988/thumbnail.jp

From Clustering Supersequences to Entropy Minimizing Subsequences for Single and Double Deletions

A binary string transmitted via a memoryless i.i.d. deletion channel is received as a subsequence of the original input. From this, one obtains a posterior distribution on the channel input, corresponding to a set of candidate supersequences weighted by the number of times the received subsequence can be embedded in them. In a previous work it is conjectured on the basis of experimental data that the entropy of the posterior is minimized and maximized by the constant and the alternating strings, respectively. In this work, in addition to revisiting the entropy minimization conjecture, we also address several related combinatorial problems. We present an algorithm for counting the number of subsequence embeddings using a run-length encoding of strings. We then describe methods for clustering the space of supersequences such that the cardinality of the resulting sets depends only on the length of the received subsequence and its Hamming weight, but not its exact form. Then, we consider supersequences that contain a single embedding of a fixed subsequence, referred to as singletons, and provide a closed form expression for enumerating them using the same run-length encoding. We prove an analogous result for the minimization and maximization of the number of singletons, by the alternating and the uniform strings, respectively. Next, we prove the original minimal entropy conjecture for the special cases of single and double deletions using similar clustering techniques and the same run-length encoding, which allow us to characterize the distribution of the number of subsequence embeddings in the space of compatible supersequences to demonstrate the effect of an entropy decreasing operation