A s a c om pl e men t t o da ta d edupli cat ion , de lta c om p ress i on fu r-
t he r r edu c es t h e dat a vo l u m e by c o m pr e ssi n g n o n - dup li c a t e
d ata chunk s r e l a t iv e to t h e i r s i m il a r chunk s (bas e chunk s).
H ow ever, ex is t i n g p o s t - d e dup li c a t i o n d e l t a c o m pr e ssi o n a p-
p ro a ches fo r bac kup s t or ag e e i t h e r su ffe r f ro m t h e l ow s i m -
il a r i t y b e twee n m any de te c ted c hun ks o r m i ss so me po t e n -
t i a l s i m il a r c hunks , o r su ffer f r om l ow (ba ckup and r es t ore )
th r oug hpu t du e t o extr a I/ Os f or r e a d i n g b a se c hun ks o r a dd
a dd i t i on a l s e r v i c e - d i s r up t ive op e r a t i on s to b a ck up s ys t em s.
I n t h i s pa p e r, w e pr opo se L oop D e l t a t o a dd ress the above -
m e n t i on e d prob l e m s by an e nha nced em b e ddi n g d e l t a c o m p -
r e ss i on sc heme i n d e dup li c a t i on i n a non - i n t ru s ive way. T h e
e nha nce d d elt a c o mpr ess ion s che m e co m b in e s f our key t e c h -
ni qu e s : (1) du a l - l o c a li t y - b a s e d s i m il a r i t y t r a c k i n g to d e t ect
po t e n t i a l si m il a r chun k s b y e x p l o i t i n g both l o g i c a l and ph y -
s i c a l l o c a li t y, ( 2 ) l o c a li t y - a wa r e pr e f e t c h i n g to pr efe tc h ba se
c hun ks to a vo i d ex t ra I/ Os fo r r e a d i n g ba s e chun ks on t h e
w r i t e p at h , (3) c a che -aware fil t e r to avo i d ext r a I/Os f or b a se
c hunk s on t he read p at h, a nd (4) i nver sed de l ta co mpressi on t o
perf orm de lt a co mpress i o n fo r d at a chunk s t hat a re o th e r wi se
f o r b i dd e n to s er ve as ba se c hunk s by r ew r i t i n g t e c hn i qu e s
d e s i g n e d t o i m p r ove r es t o re pe rf o rma nc e.
E x p e r i m e n t a l re su lts indi ca te t hat L oop D e l t a i ncr ea se s t he
c o m pr e ss i o n r a t i o by 1 .2410 .97 t i m e s on t op of d e dup li c a -
t i on , wi t hou t no t a b l y a ffe c t i n g th e ba ck up th rou ghpu t, a nd i t
i m p r ove s t he res to re p er fo r m an ce b y 1.23.57 t i m e
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Neogene sloth assemblages ( M ammalia, P ilosa) of the C ocinetas B asin ( L a G uajira, C olombia): implications for the G reat A merican B iotic I nterchange
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Algunaibet et al. (2019) reported an important and novel study linking planetary boundaries to individual sectors—in their case, electricity generation in the US—and explored designs that could keep the sector operating within a safe space. In determining the total emissions associated with electricity generation in the US, the authors multiplied electricity's life cycle emission intensities by the total generation. This method, however, commits an accounting error that can lead to overestimation. First, I use an example to illustrate, theoretically and conceptually, why it is incorrect to multiply the total output of an intermediate product, by its life cycle emission intensities. Then, I show that this overestimation error in the specific case of US electricity sector can range from 5% to 200% across different environmental impacts, using the environmentally extended input-output model of the US (USEEIO). Given the novelty and importance of their work, I encourage Algunaibet et al. to revisit their analysis using correct accounting methods.more » « less
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Abstract Tropical forests are well known for their high woody plant diversity. Processes occurring at early life stages are thought to play a critical role in maintaining this high diversity and shaping the composition of tropical tree communities. To evaluate hypothesized mechanisms promoting tropical tree species coexistence and influencing composition, we initiated a census of woody seedlings and small saplings in the permanent 50 ha Forest Dynamics Plot (FDP) on Barro Colorado Island (BCI), Panama. Situated in old‐growth, lowland tropical moist forest, the BCI FDP was originally established in 1980 to monitor trees and shrubs ≥1 cm diameter at 1.3 m above ground (dbh) at ca. 5‐year intervals. However, critical data on the dynamics occurring at earlier life stages were initially lacking. Therefore, in 2001 we established a 1‐m2seedling plot in the center of every 5 × 5 m section of the BCI FDP. All freestanding woody individuals ≥20 cm tall and <1 cm dbh (hereafter referred to as seedlings) were tagged, mapped, measured, and identified to species in 19,313 1‐m2seedling plots. Because seedling dynamics are rapid, we censused these seedling plots every 1–2 years. Here, we present data from the 14 censuses of these seedling plots conducted between the initial census in 2001 to the most recent census, in 2018. This data set includes nearly 1 M observations of ~185,000 individuals of >400 tree, shrub, and liana species. These data will permit spatially‐explicit analyses of seedling distributions, recruitment, growth, and survival for hundreds of woody plant species. In addition, the data presented here can be linked to openly‐available, long‐term data on the dynamics of trees and shrubs ≥1 cm dbh in the BCI FDP, as well as existing data sets from the site on climate, canopy structure, phylogenetic relatedness, functional traits, soil nutrients, and topography. This data set can be freely used for non‐commercial purposes; we request that users of these data cite this data paper in all publications resulting from the use of this data set.
